1. catch at 抓住，采纳。如：A drowning man will catch a straw. 快淹死的人一根稻草也要抓。They caught at the idea. 他们采纳了这个意见。
2. catch on (1) 挂住，钩住。如：Her coat caught on the nail. 她的大衣给钉子钩住了。(2) 受欢迎，流行。如：The new song caught on quickly. 那首歌很快就流行开来。(3) 领会，理解，懂得。如：He is very quick (slow) to catch on. 他理解得很快(慢)。I don’t quite catch on to what he is saying. 我不大理解他在讲什么。
3. catch sb doing sth 发现(撞见，逮住)某人正在做某事。如：The teacher caught him sleeping in class. 老师发现他在上课时睡觉。We caught him (in the act of) stealing. 他正在行窃被我们逮个正着。
4. catch sb out发现某人有错。如：Ask me anything you like --- you won’t catch me out. 你尽管问吧，决问不倒我。
5. catch up 赶上，追上。如：If you miss a lot of lessons, it’s very difficult to catch up. 要是你耽误很多课，你会很难上赶上的。Will we catch up with Japan industrial production? 我们能在工业生产上赶上日本吗? 注：catch sb up 常可与 catch up with sb 互换。如：You go ahead and I RGIN-TOP: 0cm; MARGIN-BOTTOM: 0pt; TEXT-INDENT: 21will catch you up [catch up with you]later. 我一会儿就会赶上你的。
6. catch up on (doing) sth 赶做，弥补。如：I’ve a lot of work to catch up on. 我有很多工作要赶做。I have to catch up on writing letters tonight so I can’t go out. 今晚我要赶写几封信，所以不能出去。