따져요 · 따졌어요 · 따질 거예요 · 따지세요
to argue, demand an explanation; to weigh, calculate carefully
Example
가게에 가서 왜 환불이 안 되는지 따졌어요.
I went to the store and demanded to know why I couldn't get a refund.
Good to know
따져 보다 means 'to think it over carefully': 장단점을 따져 보세요 'weigh the pros and cons.'