must tack
Regular verb: tack - tacked- tacked

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must tack
you must tack
she must tack
we must tack
you must tack
they must tack 	I must be tacking
you must be tacking
she must be tacking
we must be tacking
you must be tacking
they must be tacking	I must have tacked
you must have tacked
she must have tacked
we must have tacked
you must have tacked
they must have tacked	I must have been tacking
you must have been tacking
she must have been tacking
we must have been tacking
you must have been tacking
they must have been tacking	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must not tack
you must not tack
she must not tack
we must not tack
you must not tack
they must not tack 	I must not be tacking
you must not be tacking
she must not be tacking
we must not be tacking
you must not be tacking
they must not be tacking	I must not have tacked
you must not have tacked
she must not have tacked
we must not have tacked
you must not have tacked
they must not have tacked	I must not have been tacking
you must not have been tacking
she must not have been tacking
we must not have been tacking
you must not have been tacking
they must not have been tacking	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I tack?
must you tack?
must she tack?
must we tack?
must you tack?
must they tack? 	must I be tacking?
must you be tacking?
must she be tacking?
must we be tacking?
must you be tacking?
must they be tacking? 	must I have tacked?
must you have tacked?
must she have tacked?
must we have tacked?
must you have tacked?
must they have tacked? 	must I have been tacking?
must you have been tacking?
must she have been tacking?
must we have been tacking?
must you have been tacking?
must they have been tacking? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I not tack?
must you not tack?
must she not tack?
must we not tack?
must you not tack?
must they not tack? 	must I not be tacking?
must you not be tacking?
must she not be tacking?
must we not be tacking?
must you not be tacking?
must they not be tacking? 	must I not have tacked?
must you not have tacked?
must she not have tacked?
must we not have tacked?
must you not have tacked?
must they not have tacked? 	must I not have been tacking?
must you not have been tacking?
must she not have been tacking?
must we not have been tacking?
must you not have been tacking?
must they not have been tacking?