1. Make a general question: The guests have already left.
2. Make a special question:
The train arrived at ten o clock.
3. Make a special question to the subject:
Some robberies have happened recently.
4. Make a tag-question:
She's definitely not coming.
5. Make an alternative question:
I would like strawberry ice cream.
Have the guests already left?
When did the train arrive?
What has happened recently?
She's definitely not coming, is she?
Would you like strawberry or raspberry ice cream?