Why we can't learn English?- part 01

 We know that English is an International Language. We need to be fluent in it to do our daily activities with the international community. So, we learn English form our childhood, but we can't be an expert in English. This problem easily raises the question of why we can't?

English is a langue and also a foreign language to us. It has its own grammar, pronunciation, spelling. Now, We are Bangali. Bangla is our mother language. We learn Bangla unconsciously. 

How do we learn Bangla? At first, we hear from each other and then visualize it. We never use grammar to speak and write.