Since English is not your native tongue.

因为英语不是你的母语。

Ask-Bob-to sit-behind-me.

让鲍伯坐在我后面。

I'm not kidding.

我不是开玩笑。

The doctor did not reveal to him his hopeless condition.

医生没有向他透露说他的病已经没治了。

Don't make rude remarks about their appearances.

不要口无遮拦，批评他们的外表。

I'm sorry to keep on coughing.

我不停地咳嗽，真是抱歉。