must clump
Regular verb: clump - clumped- clumped

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must clump
you must clump
he must clump
we must clump
you must clump
they must clump 	I must be clumping
you must be clumping
he must be clumping
we must be clumping
you must be clumping
they must be clumping	I must have clumped
you must have clumped
he must have clumped
we must have clumped
you must have clumped
they must have clumped	I must have been clumping
you must have been clumping
he must have been clumping
we must have been clumping
you must have been clumping
they must have been clumping	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must not clump
you must not clump
he must not clump
we must not clump
you must not clump
they must not clump 	I must not be clumping
you must not be clumping
he must not be clumping
we must not be clumping
you must not be clumping
they must not be clumping	I must not have clumped
you must not have clumped
he must not have clumped
we must not have clumped
you must not have clumped
they must not have clumped	I must not have been clumping
you must not have been clumping
he must not have been clumping
we must not have been clumping
you must not have been clumping
they must not have been clumping	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I clump?
must you clump?
must he clump?
must we clump?
must you clump?
must they clump? 	must I be clumping?
must you be clumping?
must he be clumping?
must we be clumping?
must you be clumping?
must they be clumping? 	must I have clumped?
must you have clumped?
must he have clumped?
must we have clumped?
must you have clumped?
must they have clumped? 	must I have been clumping?
must you have been clumping?
must he have been clumping?
must we have been clumping?
must you have been clumping?
must they have been clumping? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I not clump?
must you not clump?
must he not clump?
must we not clump?
must you not clump?
must they not clump? 	must I not be clumping?
must you not be clumping?
must he not be clumping?
must we not be clumping?
must you not be clumping?
must they not be clumping? 	must I not have clumped?
must you not have clumped?
must he not have clumped?
must we not have clumped?
must you not have clumped?
must they not have clumped? 	must I not have been clumping?
must you not have been clumping?
must he not have been clumping?
must we not have been clumping?
must you not have been clumping?
must they not have been clumping?