Well I know this will come in late but I will contribute all the same
A native speaker is one who speaks the language as an L1 speaker. ie Im a nigerian I speak English not a an L1 but as an L2 because I have my own native language. It is belived that my proficiency will be better in my native languae than in English. For a native speaker the native language comes naturaly.
Cheers Aramide:
