MUST VERSUS HAVE TO

PRESENT SIMPLE
AFIRMATIVE	MUST	OBLIGACIÓN AUTOIMPUESTA ‘I must study everyday’
	HAVE TO HAS TO	NOS LO IMPONEN ‘I have to pass exams to get my degree’
NEGATIVE	MUSTN’T	PROHIBITION ‘You mustn’t giggle in class”
	Don’t / doesn’t have to	= needn’t No es necesario ‘We don’t have to get up early on Sunday’