cotton on

US /ˈkɑːt.ən ɑːn/
UK /ˈkɑːt.ən ɑːn/
"cotton on" picture
1.

明白, 領會

to understand something after a period of not understanding it

:
It took him a while to cotton on to what I was saying.
他花了一段時間才明白我在說什麼。
She finally cottoned on to the joke.
她終於明白了這個笑話。