[Peretool]

I can see that in teaching anything, mastery of the subject matter is a must.

In teaching English, the native English speakers might have a great advantage in that they have spoken the language since birth! This does not mean though that they automatically know it enough to be able to teach it.

On the other hand, there are also other nationals who, because of their education, training or experience, have acquired a level of English proficiency which approximates, or could even surpass, that of native English speakers.

Thus both groups are qualified in that particular aspect.

But the other big requirement is the ability to teach English as a second language. There are certain instructional methods and techniques which the teachers in this field need to master to be effective. And similarly, these can be acquired by a combination of education, training and experience.

So, for me, the teaching of English as a foreign (or second) language can be taught effectively by both native or non-native English speakers as long as they are qualified.