We are experimenting currently in offering translations into isiXhosa and Afrikaans alongside our normal English lectures in the Dept. Linguistics here at UWC, by uploading both text and audio translations onto the UWC Ikamva site. We offer two varieties in each case - a formal standard version with absolutely no code-switching, and the informal variety more commonly used by the students, with plently of code-switching to English. Their responses thus far has favoured the informal variety in the case of those students who self-identify as Afrikaans Hl speakers, with an even split between the formal and informal varieties of isiXhosa in the case of the isiXhosa HL speakers. In my opinion, CS is certainly working for my students, although we battle the outcries of the 'cultural custodians' of the languages in question.

I am thinking of code-switching with regard to using the culturally accepted language in the field of disability. When comparing the settings of sentences and the wordings people involved in the culture use when they talk about issues related to disability and how people in general talk about disability issues you find that it is quite different. Knowledge of these differences in language code is of utter importance to people involved in the culture, but also to people in general as the accepted code has bearings on humanities and human rights.

In Iran, code switching is a very important issue even for those who didn't learn any foreign language. People use different words from different languages and I think it really ruin the bases of both  languages. Some researchers think that it really valuable for the dynamicity of languages but I am not in favor of this belief because I truly saw its impact on my own language which was pure .However, it is totally destroyed by the Arabic language and its culture.

I am of the view that Code Switching can be used as the essential strategy for the early beginners in the beginners and early learners' classes in order to make them feel comfortable and confident to produce their sentences in a new language with the thought process they are already equipped with. Further these students are grown up and aware of the strategies to communicate in their L1. Why not ? This may be a crude beginning but it is a GOOD BEGINNING,

Code-switching is effectively used in multilingual schools in Kazakhstan as the learners have to study school subjects in three languages (Kazakh, Russian, English). 

We are experimenting currently in offering translations into isiXhosa and Afrikaans alongside our normal English lectures in the Dept. Linguistics here at UWC, by uploading both text and audio translations onto the UWC Ikamva site. We offer two varieties in each case - a formal standard version with absolutely no code-switching, and the informal variety more commonly used by the students, with plently of code-switching to English. Their responses thus far has favoured the informal variety in the case of those students who self-identify as Afrikaans Hl speakers, with an even split between the formal and informal varieties of isiXhosa in the case of the isiXhosa HL speakers. In my opinion, CS is certainly working for my students, although we battle the outcries of the 'cultural custodians' of the languages in question.

What I think about this question is, if code-switching can be used in teaching, it can make teaching a lot easier. Why I am saying that is because in many higher level institutions English is used and even though many of us know and understand English, the fact is it is not our home language to many of us and as a result we cannot easily grasp what is said in it. So if code-switching is used every now and then it can allow us to understand easily. I am looking at this at appoint where both educator and learner are bilingual or multilingual and they understand both or all languages in use.

Many thoughtful comments, very interesting. Code-switching could of course be used as a conscious teaching strategy. And I agree on that it is cognitively developing to learn and to be able to switch in-between simple and complex native language as well as in-between different languages used in other coutries. Isn't code-switching what we researchers do every day, at home with our family and children we have certain codes and when talking to collegues, presenting a paper or writing an article we use other quite different codes. Those shifts occur most often automatically without conscious thought. So code-switching is someting we learn differnet ways both from social interaction and from teaching.

Quite interesting Lisbeth. I come from a non native background which has the facility and requirement of addressing the colleagues and friends in more than three languages in order to make the ideas clear. Code switching is not a luxury but a necessity to make our points drive home. The only big difference is that we as teachers when we converse with our colleagues, code switching is not an issue at all but we are again worried too much whether we are taking students very far while using in the non native background EFL / NESB. / EFL situations.. I think we have to consider this as a learning style such as tactile, auditory or visual...

My experience in language teaching and learning the second language has mostly involved some code switching which I found useful in understanding complex concepts. Second language acquisition theories have a lot to say about this.

However, social wise, code switching is odd in formal situation. One has to stick to the preferred language when communication formal environment especially in meetings and in media statements. 

Learning a third language, Japanese however was totally different, no other language than Japanese was used and I found mastery of the basic language skills is faster this way. However,as the language concept got more complex, some intervention using the second of first language did help. of course it was kept at minimal level.

Javad has a point on code switching can ruin the language. Such act  if used in formal situations is inappropriate. the high variety - low variety of language issues. Perhaps the social learning theories would help explain the application of code switching in the society. 

As Alexandros said, "Code-switching (http://en.wikipedia.org/wiki/Code-switching) can be defined as the alternation between languages or dialects in speaking or writing in a grammatically overall consistent manner". In my opinion, some comments here show a misunderstanding of what code-switching really is, since it is sometimes confused with "mixing languages" when we speak or write. Only proficient speakers can code switch, because you need to have good knowledge of the grammatical rules of both languages, so it implies much more than just mixing languages randomly.

@Javad and Ina

Javad, how dare you infect English with the pure Persian word Iran?

Just kidding, but that seems to be your attitude.

No language is pure. Pure English is a hybrid between Anglo-Saxon (Germanic languages) and French, with a large infusion directly from Latin. It has significant elements of Greek and several other languages. You seem to use the language without protest, however.

It was the semester-long thesis of my sociolinguistics professor, Tej Bhatia, that English has survived and spread so well because it is receptive to words and constructions from other languages. I give my linguistics students a task of finding everyday English words that were borrowed from 50 different languages, and after a lot of crying, they find that they can do this almost as fast as they can write. This natural process of borrowing words and phrases cannot be stopped and it is a fact of language.

From another standpoint, think of this: Persian has developed from Old Persian, but I will bet that you would not be able to understand Old Persian any more than English speakers can understand Old English or even Middle English. So what is the pure form? Old Persian or the corrupted version of that: Modern Persian?

I agree with Glenn. Language change is not a "corruption" of the "pure" form, but something natural and really interesting to us as linguists. As Saussure once said: "Time changes all things: there is no reason why language should escape this universal law" (extracted from J. Aitchison, 2001, Language Change: Progress or Decay? New York: Cambridge University Press).

I come from a multilingual country where bilingualism and trilingualism is the norm. It is normal for teachers and students to use code-switching in the classroom, however in some English medium schools it is discouraged as they want to immerse students in an English language environment. The goal of such a school is to help students learn English and very little or no attention is being paid to regional or local languages in schools. This attitude towards languages needs to change in the third world countries in order to preserve and respect all languages. But teachers in these schools and sometimes even I used  code-switching in the classroom to help students to better understand and clarify a certain concept. You are right, code-switching should be considered a good strategy and a tool for teaching rather than a handicap.

As a matter of fact, code-switching is simply indispensable especially when teaching a foreign language at a beginner's level. The strategy however is to use it sparingly and eventually 'blot it out' as learners get to higher levels. There are times when the looks on my students' faces tell me "Sir we can't understand what u mean". I resort to code- switching at that point in time to get the message across before continuing the lesson  in the foreign language.

Glen,

In my previous comment, I agreed with Javad that code switching can ruin the language-In context of language use especially in formal situation where high variety of the language is expected. Where in my comment gave you the idea that I said language has to be pure?

While dynamism and variability is needed for a language to remain relevant to the discourse community, the high variety and low variety of language is also expected by the society especially by those that practice pluralism in language. The choice to use standard variety is expected in most formal situations. Appropriate language Register is an example of language variety choice. The language register is is usually decided depending on the social setting or particularly recognized social events.

Perhaps my explanation was not clear as such lead to Glens confusion on the last point of my previous comment. I give another try on the question by Alexandrous regarding the experience of using code switching in education. Code switching can be a useful technique at various levels of language teaching- in my case explaining the complex concept of language but not at the beginner level. However, language instructors and learners also need to be weary of code switching application by considering the sociolinguistic view on language variety - In my experience the high variety (standard variety) is expected in formal situations. In my country where language pluralism is being practice, speaking two, three or four languages is common among the professionals. But to switch from Mandarin or Cantonese dialect to English or to switch Malay language to English  during a formal event would give  a mix  impressions - suffering from English incompetency or a secret message is being sent to the respective language users only. This is the context where code switching while ignoring the language variety factor can ruin the language use. Even as Code switching in formal situation can be advantageous especially in negotiations, such code switching requires mastery beyond the linguistic skill. Awareness on language variety and register need to be understood and applied appropriately. With regards to Alexandrous question on code switching in education,apart from looking at the language teaching methodology view, considering the sociolinguistic view on language variety  can also be of benefit to the instructors and learners. 

Good morning!

Code-switching is an inevitable process in any context for several reasons. In a classroom, code-switching experience can be productive or counter-productive, depending on the angle you stand. In a language class, for instance, code-switching may bring about problems, since it may affect the nature of the language structures and phonetic aspects you are teaching. This is particularly obvious in the case of group work, when students are learning independently and may stray from the language aspect to be utilized in that particular discussion/situation. However, code-switching may be seen as natural as any language use; since, once it results in communication, there could be no "error" (I use quotation marks because I am of the opinion that as long as there is communication, there is no error, but that is a different topic).  In Jamaica code-switching is used regularly, given the fact that we have a context of bilingualism characterized by the existence of two languages that may be considered as mother tongues (of course this is a matter of contention for many, if not most). Nonetheless, it is fair to admit that Jamaicans grow switching from English to Jamaican Creole and viceversa without even noticing at times. I have researched the use of code-switching in classrooms in Jamaica, and one of my findings is the discursive use of such code-switching. I could refer you to that essay if you wish.

Good luck in your research.

Maria

@Ina

Thank you for clarifying. I guess when you write that "code-switching can ruin the language," it indicated that the language was somehow sacred and became something less because of outside influences. Indeed, the attitude that some varieties are high and others low indicates that one form is superior to others. However, I think all varieties are equally able to convey messages, but the varieties are used in different appropriate situations, some more formal than others.

I think that the definition you give to "code-switching" makes a difference in this discussion. I teach TESOL and research courses here in the Philippines, as a foreigner. My students and I have been doing a lot of research on the use of English in the Philippines. It is very common for Filipinos to code-switch between English and Filipino (the Philippine national language) when they are talking to you.

Last year, Chureson found that some of them are not aware of it. They are not aware that they are mixing English and Filipino, a language that a foreigner doesn't understand (see article at http://internationalforum.aiias.edu/images/vol16no02/2orathai_chureson.pdf).

Unfortunately, in university settings, a number of international students have reported to me that this code-switching happens a lot. One was telling me how one day she went to school and found in class that it was mid-term. The announcement about the mid-term was given in Filipino. 

From sociolinguistic perspective, I think it's perfectly find to have code-switching. But for "puristic perspective" (if ever there is anything like that), especially for academic purposes and in formal situations, code-switching (meaning switching between 2 languages, without any consideration at all wether or not the listener understand the message), code-switching should not be used. 

Safary,

similar phenomenon is happening this side too - the types of switching ranges in level - at sentence level, clause, word and even morpheme level. Yes, sometimes the speaker are not even aware of the switching. Code switching happens not just in complete form of a sentence as reported in most studies with native speakers as subjects. May I know what model have you used for your study? Perhaps Matrix Language-Frame model is suitable for  South east asia region? MLF is a model of insertional code-switching by Mayers-Scotton. I am still looking for a model on code switching with regards to Business English Lingua Franca .

Myers-Scotton, Carol (1989). "Codeswitching with English: types of switching, types of communities". World Englishes 8 (3): 333–346. 

Hi Ina,

No specific code-switching model was used. This issue simply always shows up in our data when we investigate TESOL issues in the Philippines. Please reach out to Orathai Chureson, using the link I gave, to ask her more about her study. She might have more to share. Thanks for this source by the way.

Translanguaging is useful to study in this case

Most researchers recognize the benefit of teaching a second language while making use of code switching/. The problem is very simple. The second language most taught in the world is usually English (lingua franca) and the people who control this multi-billion business do not want to give up this prestigious position of literal hegemony. The question is why are they so afraid of code switching as a potential competitive teaching method among the dozens that actually exist nowadays. The answer is very simple: Most English native speakers do not speak any second language.

Generally speaking, to preserve this linguistic imperialism ( see Philipson 1992) these big SL teaching corporations operate in two ways. First, by marginalizing, putting aside or even stifling any research that supports code switching.

Second, and to my mind is the most dangerous strategy is to encourage any research that supports the idea that any SL learner can achieve native-like competency. Such an almost impossible claim has at least two corollaries.  On the one the hand, SL learners will tend to prefer teachers who are native speakers. On the other hand, it will hide a very simple linguistic truth. No English or any language after all remains the same if it is transplanted in a different world. British English changed because it reached USA and became American English ( see Webster's interesting introduction to his first dictionary)  while it became Australian in Australia , Canadian in Canada , South African in South Africa etc...

The logical almost dangerous question is very simple: Why not recognize Chinese English, Indian English, African English etc.?

At the end of every analysis, it is all about Faucauldian notion of power and the Gramscian notion of hegemony.

An interesting thread. However, the evolution and change of a language is caused by code switching. English as an evident example, changed because the Jutes & Franks code switched between their languages.

I have conducted two research works on code-switching and code mixing in the classroom. I have not been able to publish both of them because all the Journals that I have contacted upon recommendation, say they do not publish articles written in French. If you read French, then you will find useful, the one I have already posted on researchgate entitled Pertinence de l’Alternance Codique dans une Classe de Français Langue Étrangère (FLE). Etude de Cas Chez les Apprenants et Enseignants dans Deux Lycées au Ghana. The second one that I will post this week because of you and for the sake of others who may be interested in this topic is entitled, Alternance Codique en Classe de FLE: Raisons d’Ordre Pédagogique Chez les Enseignants et Facteurs de Motivation Chez les Apprenants.

A lot of work in code switching has been dine with students whose home language is one of the many variants  of Aboriginal English. I suggest you have a look at some of the following links to the number of programs

http://www.whatworks.edu.au/4_2_1.htm

Also read Code switching: Anthropological and Sociolinguistic Perspectives, [edit Monica Heller] especially the paper by Patrick McConvell - who is now working out of AIATSIS in Canberra

In a study of multilingual Swiss schoolchildren, I found that there was one type of code switch that less proficient children used: intramorphemic switches.  While such switches were rare, they almost exclusively occurred in the speech of children who were the least proficient sequential learners of L2.  This type of switch could potentially be used as a red flag to identify children who may have undiagnosed language learning issues.  It was not the case that these switches were used by typical learners of L2; just the ones who were not acquiring at the same rate as their peers after 3 years of exposure to L2.

Code-switching at the early stage of learning a language is actually beneficial to the L2 speaker/learner. Experience have shown that most often speakers fall back to their L1 when they run short of words in their L2. But as the speaker / learner moves to advance stage of acquisition, it should be discouraged unless of course, it is used pragmatically as a sign of in-group identity.

On the one hand there is the very strict English Only policy we are following in private ESLschools throughout Canada, which is also an matter courtesy for multilingual environments, on the other hand , I am also a strong  believer of codeswitching , since it creates metalinguistic awareness and helps my students wander around between Germanic-Latin-Altaic languages. I am breaching the rules many times to explain certain word families and grammatical concepts

Thank you for raising this question, Alexandros. In my experience, code-switching is extremely valuable in the translator training, especially in undergraduate courses. Personally speaking, I use to switch between two languages - the so called language pair - that is from the students' L1 (e.g. Italian) to the students' L2 (e.g. English). This is particularly useful when one of the learning outcomes is the acquisition of appropriate specialized terminology in both L1 and L2.

I didn"t know about this issue and I learned very much hearing about your contribuitions. Thank you!

There is an educative programme on one of the Ghanaian Television Station (i.e. TV3) entitled, Ghana Most Beautiful: Redefining Beauty for National Development. Each year, the programme drew 10 ladies from the 10 regions of the country to showcase their region and to educate the public on historical events, culture and tradition and touristic sites, among others. The least education attained by the ladies who had participated on the programme was a Higher National Diploma (HND) from the Polytechnics. This meant that all the ladies had learnt English for at least 16 years and could express their ideas in it. But we noted that each of them alternated the dialect of their region with English. I observed that they did this because of a gain they wanted to take advantage of, that is, points. The people in their regions would have to vote massively for them to get more points in order to win the competition. Because of this gain, each of them quickly identified herself with her region by speaking the local language spoken there. Each of the ladies did this before code-switching into English (i.e. the official language meant for communicating their information to their immediate public, the people gathered before them in Accra). Most people in their respective regions may not understand the presentation in English but they fact that a participant on the programme had spoken their local language was sufficient enough for them to keep voting for such a participant throughout the programme.

My experience as a teacher of English at secondary school and college of education for 14 years in Botswana was that students were unwilling to use English throughout in class discussions due to a number of reasons; one being they were not fluent in the language and could not express themselves adequately in it, also because most public owned schools in the country do not have strict English speaking policies and once students notice that the teacher is a Motswana, then they want to pursue oral class activities in Setswana most of the time which does not inhibit their freedom of expression, and perhaps to show language solidarity and national identity. Teachers claim they use Setswana to explain difficult concepts to students, although lack of competence in the language may also be the reason. Students at the University of Botswana (UB) on the contrary use more English than Setswana among themselves and with their instructors. It could be because of the diversity of cultures here, the level of education attained this far, the rank of institution compared to college and secondary schools (obviously the UB is a prestigious learning institution). So, a lot of contextual issues play a role in code switching. Setswana is a national language or lingua-franca, while English is the official language in Botswana. Setswana is used as a medium of instruction at lower primary education and taught as a subject for 12 years (primary and secondary education).

In my experience taching TOEFL to college students, I have warn them - in Spanish - of the polysemic phenomenon in certain words that English language lexicographers adopted and adapted in their dictionaries, general and especialised. The most common examples are cognates and false cognates. In some other cases, I teach them to analyse, ethymologically, certain texts passages and focus our attention  in semantic boundaries key words have. I feel that if I do not do this, students simply ignore an entire lesson! Since the moment I started the code-switching, their faces show me they learn and enjoy these mentioned aspects.

dear Rafael Ibarra, I alawys codeswitch from english to french to arabic, believe me my students enjoy it very much becuase they not only hear english but they ca also see it through their own mother-tongue cognates.

Dear  Alexandros,

Please check out  my articles on this topic shared at researchgate

good luck with your research

a.

Sometimes it is necessary for you to code-switch if your students have difficulty in understanding the lesson. It is better for them to at least really understand the lesson rather than they just sitting in the classroom. Normally,I code switch for jokes (Malay language) because they didn't find it funny if I use English for jokes. 

Dear all,

I have been teaching English to University students from 1996. Most of my students if not all of them, English was their third language after Kinyarwanda and French. It was a rule that teachers should exclusively teach everything in English so that the students become familiar with English sound and its use. However, there were times we violated the rules and and had to explain difficult concepts in Kinyarwanda or French for the good of students. You can see examples especially in the articles on 'Language and space in a multilingual undergraduate physics classroom in Rwanda' and 'Negotiating meaning in multilingual group work: a case study of higher education in Rwanda'

Enjoy

Please refer to the following article:

Noori, A., Rasoly, N. (2017). Afghan EFL Lecturers’ Perceptions of Code-Switching. INTERNATIONAL JOURNAL FOR INNOVATIVE RESEARCH IN MULTIDISCIPLINARY FIELD, 3(12), 52-58.

Hi Alex,

As someone who is multi-lingual, has taught bilingual children and a Speech Therapist- being able to code switch is a must in a multi-lingual environment not only from an academic point of view but from a social persective. It helps people to bond, to relate to others on their level and even 'invent' new terminology. From an acedemic perspective it builds on the semantics system and ingetragtes new learning into one system. Explanations definitely need to be done in both languages to aid understanding of difficult concepts.

Hope that helps.

hi. codeswitching is a natural tendency of l2 learners of the same l1. some students code-swtich unconsciously while taking part in conversation. it is a useful tool to be used in language teaching and learning. instead of translating a sentence into l1, you can allow your students to code-switch when they do not know the words in l2. it enhances students' exposure to l2 structures. it allows them to use the integrates system of language learning simultaneously; students are afraid of not knowing the words. so they donot take part in conversations. if they know that they can convey the message by different means, they can engage in interactions.best

Code switching is the norm in multilingual contexts. In most instances, the speakers are not even aware of it. They simply use what is in their linguistic system as per demand.

Code switching should be embraced in social and academic settings as a way of recognizing the varied roles of the different languages one knows. This should be the norm in a world that is getting more and more multilingual.

Some time ago, while conducting research in Montreal, I used to teach Greek at the local Greek school, to 2nd, 3rd and even 4th generation Greeks born and raised in Canada. As a neurolinguist, I had studied and taught code-switching aspects of brain organization, but never before my Montreal experience did I fully realize what code-switching in everyday life and activity really means. I am multilingual myself, so our classes were a continuous travel among English, French (most of my students were basically Quebec French speakers although English proficient of course) and basic Greek that some of them had inherited from great-grandparents even in funny dialectal forms. Living in Montreal means code-switching in the middle of the phrase on regular bases. Teaching foreign languages and doing neurolinguistic research on code-switching in Montreal means moving from theory to practice in the most amazing and challenging way of all.

In my opinion, code switching/code mixing may be a very appropriate method of teaching where a language foreign to the learners is the medium of instructions. In such cases, a teacher may "code switch" to a language that the learners understand better to explain unfamiliar concepts or content. This would lead to a better understanding.

In the context of the South African classroom it is necessary to make use of code-switching while teaching in order for all the learners to understand the content you are trying to convey.

In the previous dispensation (Apartheid-South Africa) learners from different racial backgrounds were segregated and were not allowed to attend the same schools. Now, in post-Apartheid South Africa, every child is free to attend any school of his or her choice. The language question in South Africa is very complex, however. We have 11 official languages and in order not to discriminate against any, it was decided that in every province we should focus on the languages that are dominant in that province.

We have scenarios where learners often do not understand the language of teaching and learning and even those who have English as their mother tongue, do not speak the standard variant. Where Afrikaans is concerned, learners often do not speak or understand the standard variant, but speak the variant commonly referred to as 'Kaaps' (from the Cape Flats, which is an area in Cape Town predominantly inhabited by the group of South African society that are still statutorily referred to as 'Coloureds). In South Africa there is a distinct difference between Black and Coloured, unlike in countries like the USA, where 'Black' and 'Coloured' are used interchangeably. Black and Coloured in South Africa have different cultures, languages, rituals, beliefs, etc.

All these learners from this diversity share the same spaces and it is important for the educator to find ways to make every child feel safe, welcome and 'part of', and it is therefore important that they make use of code-switching in order to achieve that. It will ultimately also contribute to better discipline in the classroom.

In my opinion, code-switching may be useful as a tool to foster translanguaging (Garcia, 2009) in the classroom, and students' bilingual potential within bi-/multilingual contexts.

I think it depends on several factors, including how advanced the students are. There should certainly be blocks of classroom time that are all in the language being learned. But I also think it is reasonable for certain portions, like the beginning and end of the class, to be in the students' native language, so the teacher can ensure that they understand instructions, etc.

I agree with most of the sharers, Code switching is a norm in a multilingual/bilingual ecology. It's a language phenomenon which we should celebrate and embrace in the classroom especially when the students seem to struggle expressing their thoughts in pure English.

Local studies in my country show that CS in the classroom is not always deficiency driven. CS performs communicative and pragmatic functions.

The old Bilingual Education Policy and now the MTB-MLE, I think, will make the code-switched English and Tagalog/other Philippine languages a feature of Philippine classroom language.

A local study conducted in Mathematics classes, it proves that contrary to some views that code-switching is a negative linguistic phenomenon to be avoided in the classroom, codeswitching can be used as an aid to teaching math concepts and problem solving processes.

It is argued by some university authorities that code switching will reduce the chances of students to communicate in English as a medium of instruction, but I witnessed code-switching as a good strategy to help science students internalize complex concepts into their mental lexicon. A concept is better understood beginning with one's mother tongue

Thanks Sir Alexandros!

Code-switching in only important when English is not understandable specially in multilingual context.

Teachers employ code switching as a means of providing students with the opportunities to communicate and to enhance students’ understanding. Furthermore, code switching helps to facilitate the flow of classroom instruction since teachers would not have the luxury of time trying to explain to the learners or searching for the simplest words to clarify any confusion that might arise. Code-switching should not be considered as a sign of shortcoming in the teacher. Instead, it is a careful strategy that must be employed by language teachers sparingly and when/where necessary, most especially, beginning learners of a language.

As a student, I personally do think that code switching sometimes helps in lectures. As not everyone's mother tongue is in English and especially if the lecturer is teaching in multilingual classes. However, it is also best not to overuse the code switching strategy, as sometimes it might also affect the learner to improve more on their vocabularies. Being subtle is just alright.

It is necessary to make use of code-switching while teaching in order to make sure that the learners can understand the content the teacher is trying to convey, and to develop curiosity.

In retrospect, the default academic situation is that people speak one language at a time. It forms the basis for linguistics, sociolinguistics, and this discussion about code-switching. Why not take it, if just for fun, from the perspective that the default is that people use whatever linguistic tools are at their disposal regardless of how we might categorize what belongs to what language?

Recently, I listened as my Mexican neighbor, who has very limited English, conversed with my son, who picked up limited Spanish from co-workers over the past decade or so. With each understanding very little of each other's native vocabulary and unable to execute any formal syntax of either, they augmented the words with gestures and expressions. Somehow at the end of the discussion they reached an understanding, nodding their heads in approval and smiling.

Does that situation describe the norm, or does communication grow from a formal internalized grammar of more than one language?

(I may turn this idea into a separate discussion.)

In my experience code-switching may be useful when it is used with a specific purpose in mind: for example to make your students focus on something especially if you have noticed that they are not listening carefully or that they got used to the tone of your voice/rhythm/intonation. In that context, a sudden "switch" may serve as a trigger for drawing attention to the point you want to make :)

Agree completely with Diana. Took me some years as a teacher/professor to develop the skills and pedagogical knowledge to learn when such code-switching was needed AND how to carry it off effectively.

Switching codes from the target to the mother language or vice versa is important , especially in discussing grammatical structures and other spelling rules. But code switching is better avoided when it comes to teaching speaking and listening.