when the students can speak Cninese appropriately based on the context.......

Learners with a high sense of self efficacy will persist longer at language learning tasks, exert more effort and employ language learning strategies successfully. They believe they have control over the learning outcomes and thus have high expectations so normally demostrate goal directed behaviour . (see Oxford 1999).

I´m not sure I fully understand what you mean by their characteristics in learning Chinese. In any L2 learning context the learner who considers herself highly efficacious will display some or all of these characteristics.

First of all, it is necessary to know the different between second and foreign language. in case of Chinese, I think, English is used as a foreign language. second, the term of self efficacy has a variety in using. in your case, it is used to measured foreign language but students themselves who should be asked. finally, i can say, this is a qualitative question can be involved in a study.

When the students can speak english appropriately based on the context.......

In my opinion It depends on several features:

1. Motivation and interest in learning Chinese.

2. The first language (L1) of the learner. (It's not the same having a Romance language that an Asian language like Japanese or Korean)

3. The type of written exercises performed (characters / yong, strokes and their layout components, semantic groups, words ...).

4. Work on phonetic parts: pronunciation and intonation.

5. The systematization of exercises that engage in a global view of the structure of Chinese.

6. Readings.

7. Knowing the history of the language (ancient, simplified).