動詞 catch on:

1. understand, usually after some initial difficulty
   同義詞：get wise, get onto, tumble, latch on, cotton on, twig, get it
2. become popular

1. It is a nice song and I think it will catch on quickly.
   這首歌很好，我想它會很快流行起來。
2. He's always the last to catch on.
   他總是最后一個弄明白。
3. The catch on my handbag is broken.
   我的手提包的扣壞了。
4. I didn't catch on to this joke.
   我沒明白這個笑話。