say what?
US /seɪ wʌt/
UK /seɪ wʌt/

1.
wat zeg je?, wat?
used to express surprise or to ask someone to repeat something because you did not hear or understand it
:
•
I just won the lottery! Say what?
Ik heb net de loterij gewonnen! Wat zeg je?
•
You want me to work on Saturday? Say what?
Je wilt dat ik op zaterdag werk? Wat zeg je?