cotton on
US /ˈkɑːt.ən ɑːn/
UK /ˈkɑːt.ən ɑːn/

1.
capire, afferrare
to understand something after a period of not understanding it
:
•
It took him a while to cotton on to what I was saying.
Ci è voluto un po' prima che capisse cosa stavo dicendo.
•
She finally cottoned on to the joke.
Alla fine ha capito la battuta.