It's a very easy, very direct, not at all impolite way to express your desires in any situation.

这是个非常简单而直接的句型，用这样的句型在各种情形下表达你的愿望也不会显得不礼貌。

I want to 课堂 - SpeakingMax英语口语达人

It's a really disgusting habit and you have to stop doing this. It's so impolite.

这真是个令人作呕的习惯。你一定要改掉。这样太没礼貌了。

have to 实战 - SpeakingMax英语口语达人

Your waiter is impolite.

服务员很没有礼貌。

Let's 课堂 - SpeakingMax英语口语达人