PHRASAL VERB 明白;领悟;意识到 If you cotton on to something, you understand it or realize it, especially without people telling you about it. 明白;领悟;意识到 [British, informal]
She had already cottoned on to the fact that the nanny was not all she appeared. [VERBPREP. + to]
她已经意识到这个保姆不只是她看起来的那样。
It wasn't until he started laughing that they cottoned on! [VERBPREP.]