Some student think that if the foreigner teacher can speak their mother tongue,it will more easy to make they understand,but ,if like this,why not just use their country's teacher
It's not totally necessary. But, it can be an advantage. I teach English to ESL students from China and some students who are super beginners are having difficulties understanding English. I happen to know how to speak Chinese at a conversational level (evidently, with pretty bad pronunciation) and it became easy for them to understand. If you know how to speak their language, it can be pretty handy based on my teaching experience. :)
It's not totally necessary but useful because you can understand the reason why students make some kind of mistakes.
I find it totally necessary at the beginning stages. The students come in contact with a brand new concept and need to understand it before they can try to use it. That's why many people use teachers that are not native speakers but have a good command of the foregn language.
When the native speaker says "Hello", the students need to know what it means in their own language and how to use it.
The native speaker is necessary after the student has already understood the concepts and the basic terms and wants to learn how to use the language in a "correct" and natural way.
If the teacher - native speaker also speaks the students' language, this is a double benefit for the student.
I think it's better to rely on translation for a while. If the teachers can't explain what they're teaching, I might be learning the wrong thing.
When the teacher says "I am .....", in a completely new language for me, I might think they say "Hello", "My name is..", "Goodmorning" or even "I am your teacher".
I wouldn't like to spend valuable time guessing what they mean and how it applies. I'd rather have it translated until I can understand enough of the foreign language to be able to guess it myself.
that's right,but ,if i use their native language to teaching,the student will rely on native language, don't want to think about what I'm said in foreign language, but waiting for me to translate for them.