I am surprised at the audacity expressed in these posts. Native speakers make mistakes but I think they would correct them before posting. There are glaring grammar mistakes in almost every pro non-native post. If you can't see them or don't think that matters, then I pity your students whose papers you are correcting. It is true that some native speaking teachers are not as good as non-natives in explaining complex grammar, but I have heard non-native teachers pronounce words so incorrectly that most of there students had the same incorrect pronunciation. For example, Dat instead of That is just wrong for a student paying to learn English for business! It's a shame!
—Guest Elizabeth