The ministry of higher and secondary special education of the republic of uzbekistan

have (got) to	There is no past form of «must». Expressions of past necessity are generally presented via the form have to for obligations and conclusions. In the present tense have to can be used in a wider range of constructions than must. As uncontrollable external source that compels an action. More typically found in informal speech have got to is used with the root meaning of obligation. It does not occur with other modal forms. Mustn’t conveys an obligation not to do something, whereas don’t have to means that there is not an obligation to do something.
a) When I was in school, we had to wear school uniform. b) He was really dig, he had to be over 7 feet tall. a) Do we really have to go this meeting? b) Yes, and we will have to present our report. a) Excuse me, but I have to sneeze. a) They’ve got to try harder next time. a) You mustn’t drink beer. b) You don’t have to drink beer.
be going to (the immediacy)	It is not used to express the «willingness» associated with «will». The future action is related to the present and will occur soon after the time of speaking. The action with be going to was already planned or decided. CF: I’m gonna be sick (the reduced form of casual speech shown); I will be sick (if I eat any more of this ice cream).	a) I’m going to finish these exercises. b) And I’ll get round to the others later. a) Close your eyes, I’m going to give you surprise. b) Watch out! The monster is going to get you.