must lip
Regular verb: lip - liped- liped

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must lip
you must lip
he must lip
we must lip
you must lip
they must lip 	I must be liping
you must be liping
he must be liping
we must be liping
you must be liping
they must be liping	I must have liped
you must have liped
he must have liped
we must have liped
you must have liped
they must have liped	I must have been liping
you must have been liping
he must have been liping
we must have been liping
you must have been liping
they must have been liping	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must not lip
you must not lip
he must not lip
we must not lip
you must not lip
they must not lip 	I must not be liping
you must not be liping
he must not be liping
we must not be liping
you must not be liping
they must not be liping	I must not have liped
you must not have liped
he must not have liped
we must not have liped
you must not have liped
they must not have liped	I must not have been liping
you must not have been liping
he must not have been liping
we must not have been liping
you must not have been liping
they must not have been liping	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I lip?
must you lip?
must he lip?
must we lip?
must you lip?
must they lip? 	must I be liping?
must you be liping?
must he be liping?
must we be liping?
must you be liping?
must they be liping? 	must I have liped?
must you have liped?
must he have liped?
must we have liped?
must you have liped?
must they have liped? 	must I have been liping?
must you have been liping?
must he have been liping?
must we have been liping?
must you have been liping?
must they have been liping? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I not lip?
must you not lip?
must he not lip?
must we not lip?
must you not lip?
must they not lip? 	must I not be liping?
must you not be liping?
must he not be liping?
must we not be liping?
must you not be liping?
must they not be liping? 	must I not have liped?
must you not have liped?
must he not have liped?
must we not have liped?
must you not have liped?
must they not have liped? 	must I not have been liping?
must you not have been liping?
must he not have been liping?
must we not have been liping?
must you not have been liping?
must they not have been liping?