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 mustn't cluster you mustn't cluster he mustn't cluster we mustn't cluster you mustn't cluster they mustn't cluster	I mustn't be clustering you mustn't be clustering he mustn't be clustering we mustn't be clustering you mustn't be clustering they mustn't be clustering
Perfect	V-ing perfect
I mustn't have clustered you mustn't have clustered he mustn't have clustered we mustn't have clustered you mustn't have clustered they mustn't have clustered	I mustn't have been clustering you mustn't have been clustering he mustn't have been clustering we mustn't have been clustering you mustn't have been clustering they mustn't 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
mustn't I cluster? mustn't you cluster? mustn't he cluster? mustn't we cluster? mustn't you cluster? mustn't they cluster?	mustn't I be clustering? mustn't you be clustering? mustn't he be clustering? mustn't we be clustering? mustn't you be clustering? mustn't they be clustering?
Perfect	V-ing perfect
mustn't I have clustered? mustn't you have clustered? mustn't he have clustered? mustn't we have clustered? mustn't you have clustered? mustn't they have clustered?	mustn't I have been clustering? mustn't you have been clustering? mustn't he have been clustering? mustn't we have been clustering? mustn't you have been clustering? mustn't they have been clustering?