i agree with this statement..

for language teacher excellent english is a must.. but in teaching other subjects like math talking good english dont mean your are good in teaching math..

it would be perfect though if he does have both.

native speakers are so lucky, they hear and use english language ryt after they were born. why i am telling this??

most asians that grew up and live in the UK and US speak your laguage fairly.. becoz they hear and use it ryt after birth aswell..