你出生后你父母结的婚？还是，你出生后你父母结婚了没有？
-It should be "你出生后你父母结的婚？". "Marry" mean the event (事件）of marriage takes place. "
So, "did your parents marry after you were born" means "Did your parents' marraige take place after you were born?".
"你出生后你父母结婚了没有？" should be "Were your parents marred after you were born?".
"Were married" indicates the status of marriage （状况、状态） existing (i.e., the marriage exists).
