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