It is bad manners to talk with your mouth full.

嘴里塞满了东西跟人说话是不礼貌的。

Many visitors complained of his bad manners and self-importance.

许多访客抱怨他的不礼貌和妄自尊大。

Bad manners of these Chinese visitors, such as stepping on the grass and littering garbage everywhere would give all Chinese a bad name.

这些中国游客的不良行为，如踩踏草坪和乱扔垃圾等，会抹黑所有中国人的名声。

It is bad manners to stare at people.

瞪着眼睛看人是不礼貌的。

I am sick of his bad manners.

他的不良举止真让我厌恶。