Must and Have to, can be used to express obligations. Simply put: Must expresses a personal obligation while Have to an impersonal obligation or a fact. As Christmas is not far off my mother has given me the following obligations:
Well, my plan is to avoid going back to the UK for Christmas so I don’t have to do any of the above. Furthermore, I would rather slit my own wrists and cut out my tongue than drink eggnog. Eggnog is for nutjobs and dairy lovers!
Seriously, what’s the problem with looking like a scarecrow, talking about my new favourite Spanish sitcom, ‘Gym Tony’, and drinking vodka?