''what'' vs. ''yes''
I once said "what" to my ESL teacher when he called my name and my ESL teacher said "Don't say "what", say "yes""
Here's my question:
What's with my ESL teacher? Why should I say "yes" instead of "what"? What's wrong with ''what''?
It sounds rude to say what when answering to your name. In my mind it's said in the mindset of "What do you want?!" Don't know why this comes to mind though.
If you responded with "what", and your ESL teacher is a native English speaker, they could have interpreted it in one of two ways: if your intonation rose over the course of saying the word or was steady at a higher pitch, it would mean "what did you say?", which isn't necessarily rude, but likely implies that you weren't paying attention; or if your intonation lowered over the word, or was steady at a lower pitch, it means "what do you want?" which also isn't particularily rude, but can be construed that way. So be very carefully in situations like these, as your intonation can dramatically alter the meaning (not as much as in Chinese, but still...)
<<It sounds rude to say what when answering to your name.>>
That depends on the tone of your voice when you're saying it.
What the above posters say about intonation is true, however, I did not get the impression from your question that you did not hear her and were asking her to repeat herself. I got the impression that you heard and answered with "what" - which can be construed as rude by some. I actually think it is very rude. I guess not all people feel the same though.
<<I got the impression that you heard and answered with "what">>
That's exactly what I did.