must clump
Regular verb: clump - clumped- clumped

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