put two and two together
US /pʊt tuː ænd tuː təˈɡɛðər/
UK /pʊt tuː ænd tuː təˈɡɛðər/
1.
to deduce the truth from obvious clues or information
:
•
When I saw them together, I immediately put two and two together and realized they were dating.
•
She didn't tell me directly, but I could put two and two together from her hints.