must lap
Regular verb: lap - lapped- lapped

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must lap
you must lap
he must lap
we must lap
you must lap
they must lap 	I must be lapping
you must be lapping
he must be lapping
we must be lapping
you must be lapping
they must be lapping	I must have lapped
you must have lapped
he must have lapped
we must have lapped
you must have lapped
they must have lapped	I must have been lapping
you must have been lapping
he must have been lapping
we must have been lapping
you must have been lapping
they must have been lapping	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I mustn't lap
you mustn't lap
he mustn't lap
we mustn't lap
you mustn't lap
they mustn't lap 	I mustn't be lapping
you mustn't be lapping
he mustn't be lapping
we mustn't be lapping
you mustn't be lapping
they mustn't be lapping	I mustn't have lapped
you mustn't have lapped
he mustn't have lapped
we mustn't have lapped
you mustn't have lapped
they mustn't have lapped	I mustn't have been lapping
you mustn't have been lapping
he mustn't have been lapping
we mustn't have been lapping
you mustn't have been lapping
they mustn't have been lapping	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I lap?
must you lap?
must he lap?
must we lap?
must you lap?
must they lap? 	must I be lapping?
must you be lapping?
must he be lapping?
must we be lapping?
must you be lapping?
must they be lapping? 	must I have lapped?
must you have lapped?
must he have lapped?
must we have lapped?
must you have lapped?
must they have lapped? 	must I have been lapping?
must you have been lapping?
must he have been lapping?
must we have been lapping?
must you have been lapping?
must they have been lapping? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
mustn't I lap?
mustn't you lap?
mustn't he lap?
mustn't we lap?
mustn't you lap?
mustn't they lap? 	mustn't I be lapping?
mustn't you be lapping?
mustn't he be lapping?
mustn't we be lapping?
mustn't you be lapping?
mustn't they be lapping? 	mustn't I have lapped?
mustn't you have lapped?
mustn't he have lapped?
mustn't we have lapped?
mustn't you have lapped?
mustn't they have lapped? 	mustn't I have been lapping?
mustn't you have been lapping?
mustn't he have been lapping?
mustn't we have been lapping?
mustn't you have been lapping?
mustn't they have been lapping?