what's this in english?that's a good question.when we were learning english as a chinese,we must open our mouth to say something,ask some questions,then you can prove yourself.I think the sentence" what's this in english?" is a very good question,you can use it when you didnt know anything is.then you can remember it.
however,we learn language for communication,and to let you can understand the meaning of some articles or newspapers.of course,also to pass the exams.this question told us that it is very importent to open your mouth when you are learning a language,when u received any answers,your memories of the word or any other messages will be deepen,then you can use it in your daily time.
so to open your month were not even benifit of your language learning,but also of other aspects.just open your mouth and say what you want.