Definition of first language?

Question:

I am Japanese and I was born in Japan.
However, I moved over to England when I was 2 and I believe I am slightly better at English than Japanese. I am fluent in Japanese except I think I can express myself better in English. So for me, what is my first language? Is it your best language or literally the first language you learnt even if it isn't your best language?

Ps Universities say that A levels in a foreign language doesnt "count" if its your first language. I already have a Japanese A level so Im wondering if it "counts" or not ;)

Answer:

If you need the A level to "count" then you should list English as your first language. Most children do not start speaking until around age two, so you essentially have two first languages. You were raised bilingual.