|part of speech:
||to have the necessity to do something; be required to; must.
We have to finish the project by Friday.You don't have to stay here; you can go home now.
||used to make a confident judgment about something based only on logic rather than knowledge of the facts; must (used in affirmative statements only).
This has to be the right house; look at all the cars in front.There has to be gas station somewhere around here.