On top of sth. 完全控制，做得好

Do you think he's really on top of his job?

你覺得他把自己的工作能做好嗎？

A: How is the new project going?

新項目咋樣？

B: Don’t worry. I was on top of it while you were on vacation.

別擔心。你度假不在的時候，我做得很好。

On top of it/that

而且，還（描述不愉快的事情）

We missed our flight, and on top of that we had to wait seven hours for the next one.

我們沒趕上航班，而且下一班還得再等7個小時。

top n. 上衣

I need a top to go with these trousers.

我需要一件上衣配這條褲子。

From top to bottom 徹底

She searched the apartment from top to bottom for the missing letters.

為了找那些丟了的信，她把整個房子徹底翻了一遍。

On top of the world 極度開心

I’m on top of the world; I’ve just had a baby son.

我開心死了！我剛有了個兒子！