QUESTION for FINISHED ACTION
DID SOMETHING HAPPEN?
DID HE GO TO CHINA?
HAVE YOU BOUGHT A CAR?
DID HE TELL YOU?
To ask if something happened (or has happened), we use the construction 有没有 /yǒu-meiyou/
We don’t use this construction to ask what or when or where or how something happened
We don’t use 了 /le/
DID SOMETHING JUST HAPPEN?
DID YOU (JUST) EAT?
DID YOU (JUST) BUY A BOOK?
To ask whether something JUST HAPPENED, we use 了吗 /lema/ at the END of a sentence
WHAT DID YOU SAY?
WHAT DID YOU BUY?
To ask what happened, we ask question using a question word 什么 /shénme/
The question is a standard question just like in “present tense”, only with the difference that we put 了 /le/ behind the verb
When we already know that something happened and we want to know more (like WHEN or WHERE or BY WHO) something happened, we use the construction CIRCUMSTANCES OF THE EVENT