1) Did they open the window? (This is general question) 2) Did they open or close the window? (This is alternative question) 3) When did they open the window? (This is special question) 4) They opened the window two hours ago, didn't they? (This it's tag-question) 5) Who opened the window? (This is question to the subject)
(This is general question)
2) Did they open or close the window?
(This is alternative question)
3) When did they open the window?
(This is special question)
4) They opened the window two hours ago, didn't they?
(This it's tag-question)
5) Who opened the window?
(This is question to the subject)