It is my opinion that better understanding is derived when students are taught using their native dialect. A difficult mathematical concept could be explained using pidgin English.
Well sometimes it is better to emphasise a specific problem by using "native dialect", but in general, the student must learn how to understand the scientific problems by using the simple science terms and symbols (the symbols and terms abbreviate a lot of talking), then they will be able to discuss with natives or foreigners (certainly in the same field).
And I totally agree with Napoleon Ono Imaah with his last phrase.
Yes, it helps but it has some disadvantages. Imagine a Yoruba man that does not understand English language being taught Economics subject in Yoruba language. On the day of examination, who will interpret the questions to him?
Students will understand pretty well when we teach in native language. The reason is learning something in their native leads to emotional attachment. Human learns better only when they get connected emotionally and they gain intrinsic motivations. Curiosity and motivation are two factors influences a lot towards the quality of learning.