English verb conjugation
MUST CLUSTER

Regular verb: cluster - clustered - clustered

Affirmation

Simple form	V-ing form
I must cluster you must cluster he must cluster we must cluster you must cluster they must cluster	I must be clustering you must be clustering he must be clustering we must be clustering you must be clustering they must be clustering
Perfect	V-ing perfect
I must have clustered you must have clustered he must have clustered we must have clustered you must have clustered they must have clustered	I must have been clustering you must have been clustering he must have been clustering we must have been clustering you must have been clustering they must have been clustering

Negation

Simple form	V-ing form
I must not cluster you must not cluster he must not cluster we must not cluster you must not cluster they must not cluster	I must not be clustering you must not be clustering he must not be clustering we must not be clustering you must not be clustering they must not be clustering
Perfect	V-ing perfect
I must not have clustered you must not have clustered he must not have clustered we must not have clustered you must not have clustered they must not have clustered	I must not have been clustering you must not have been clustering he must not have been clustering we must not have been clustering you must not have been clustering they must not have been clustering

Interrogative form

Simple form	V-ing form
must I cluster? must you cluster? must he cluster? must we cluster? must you cluster? must they cluster?	must I be clustering? must you be clustering? must he be clustering? must we be clustering? must you be clustering? must they be clustering?
Perfect	V-ing perfect
must I have clustered? must you have clustered? must he have clustered? must we have clustered? must you have clustered? must they have clustered?	must I have been clustering? must you have been clustering? must he have been clustering? must we have been clustering? must you have been clustering? must they have been clustering?

Interro-negative form

Simple form	V-ing form
must I not cluster? must you not cluster? must he not cluster? must we not cluster? must you not cluster? must they not cluster?	must I not be clustering? must you not be clustering? must he not be clustering? must we not be clustering? must you not be clustering? must they not be clustering?
Perfect	V-ing perfect
must I not have clustered? must you not have clustered? must he not have clustered? must we not have clustered? must you not have clustered? must they not have clustered?	must I not have been clustering? must you not have been clustering? must he not have been clustering? must we not have been clustering? must you not have been clustering? must they not have been clustering?