Because it’s so common to make information questions using "have to," this lesson is on just that. The most important thing to remember is that the helping verbs and the modal verbs determine the tense.
Present Tense
Question:
Where do you have to go today?
Answer:
I have to go to work.
Where does he have to go today?
He has to go to work.
How many shirts do I have to buy to get one free?
You have to buy two shirts to get one free.
Past Tense
Question:
Why did you have to see the doctor?
Answer:
I had to get my blood pressure checked.
How much did he have to pay for tuition?
He had to pay over $3000.
Why did they have to leave?
They had to attend a wedding.
Future Tense
Question:
How long will I have to take this medication?
Answer:
You‘ll have to take it until the pain goes away.
When will she have to be there?
She’ll have to be there by 2:00.
Notice that you can also use the present tense when asking about the future.
How long do I have to take this medication?
You have to take it until the pain goes away.
When does she have to be there?
She has to be there by 2:00.
While "have to" is typically used for the present, past, and the future, it is occasionally used with the present perfect tense; however, sometimes it’s difficult to apply "have to" when making a question in this tense.
Present Perfect Tense
Question:
Why have they had to cut back on their spending? (Or…Why have they needed to cut back on their spending?)
Answer:
They’ve had to cut back on their spending because he lost his job.
How long has he had to use a cane to get around?
He’s had to use a cane for the last couple of years.
or…
How long has he used a cane to get around? (It’s not necessary in some cases to use the present perfect with "have to" when making a question.)
He’s had to use a cane for the last couple of years.
You can also make questions with modal verbs and "have to," but aside from "will," the modal verb most commonly used is "should."
Present Perfect Tense
Question:
Why should we have to pay our taxes if we aren’t happy with the way government operates/
Answer:
We should have to pay our taxes because it’s the law and because the government provides essential services.
Practice
You’re given the answer to a question. Make the question using "have to" and the question words provided. Write your answers in a notebook:
1. What time ________________________________________________?