The structure have (got) to is used to talk about obligation. It has a similar meaning to must.
- I have got to get up early tomorrow. (= I must get up early tomorrow.)
- I have got to meet him.
- I have got to go now.
Have got to can also be used to show certainty. This usage is very common in American English.
- I don’t believe this. You have to be joking. / You have got to be joking. (= You must be joking.)
In this structure questions and negatives can be made with or without do.
- I have to see him. / I have got to see him.
- Do you have to see him? / Have you got to see him?
- No, I don’t have to see him. / No, I haven’t got to see him.
We do not usually use have got to to talk about repeated obligation.
- I usually have to get up early in the morning. (NOT I usually have got to get up early in the morning.)
To talk about future obligations that already exist, we can use have to or have got to. To talk about a purely future obligation, we use will have to.
- I have got to see him tomorrow. (The obligation already exists.)
- One day everybody will have to get permission to buy a vehicle.