Final answer:
To change the given sentences into questions, add the appropriate question word at the beginning of each sentence.
Step-by-step explanation:
1. [What does he teach?]
What does he teach?
2. [Does he eat something?]
Does he eat something?
3. [Do you work somewhere there?]
Do you work somewhere there?
4. [Do they have to go there?]
Do they have to go there?
Learn more about Changing sentences into questions