must sag
Regular verb: sag - sagged- sagged

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must sag
you must sag
she must sag
we must sag
you must sag
they must sag 	I must be sagging
you must be sagging
she must be sagging
we must be sagging
you must be sagging
they must be sagging	I must have sagged
you must have sagged
she must have sagged
we must have sagged
you must have sagged
they must have sagged	I must have been sagging
you must have been sagging
she must have been sagging
we must have been sagging
you must have been sagging
they must have been sagging	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must not sag
you must not sag
she must not sag
we must not sag
you must not sag
they must not sag 	I must not be sagging
you must not be sagging
she must not be sagging
we must not be sagging
you must not be sagging
they must not be sagging	I must not have sagged
you must not have sagged
she must not have sagged
we must not have sagged
you must not have sagged
they must not have sagged	I must not have been sagging
you must not have been sagging
she must not have been sagging
we must not have been sagging
you must not have been sagging
they must not have been sagging	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I sag?
must you sag?
must she sag?
must we sag?
must you sag?
must they sag? 	must I be sagging?
must you be sagging?
must she be sagging?
must we be sagging?
must you be sagging?
must they be sagging? 	must I have sagged?
must you have sagged?
must she have sagged?
must we have sagged?
must you have sagged?
must they have sagged? 	must I have been sagging?
must you have been sagging?
must she have been sagging?
must we have been sagging?
must you have been sagging?
must they have been sagging? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I not sag?
must you not sag?
must she not sag?
must we not sag?
must you not sag?
must they not sag? 	must I not be sagging?
must you not be sagging?
must she not be sagging?
must we not be sagging?
must you not be sagging?
must they not be sagging? 	must I not have sagged?
must you not have sagged?
must she not have sagged?
must we not have sagged?
must you not have sagged?
must they not have sagged? 	must I not have been sagging?
must you not have been sagging?
must she not have been sagging?
must we not have been sagging?
must you not have been sagging?
must they not have been sagging?