Verb form is the form of the verb in one sentence that can control, determine, or limit the choice of the verb form in the next sentence. We may be justified in saying that a verb form in one sentence is “wrong”, or at least “unlikely”, because it doesn’t fit with the form in another. We can see that all the verbs (is going to, has got to, am not going to) are all in the present (although they refer to the future). There seems to be a way in which the verb form in the first sentence conditions all the others.