catch someone's drift
US /kætʃ ˈsʌm.wʌnz drɪft/
UK /kætʃ ˈsʌm.wʌnz drɪft/

1.
to understand the general meaning or intention of what someone is saying
:
•
I think I catch your drift; you want me to finish this by tomorrow.
•
He spoke vaguely, but I still managed to catch his drift.