must cluster
Verbo regular: cluster - clustered- clustered

Afirmação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I must cluster
you must cluster
she must cluster
we must cluster
you must cluster
they must cluster 	I must be clustering
you must be clustering
she must be clustering
we must be clustering
you must be clustering
they must be clustering	I must have clustered
you must have clustered
she 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
she must have been clustering
we must have been clustering
you must have been clustering
they must have been clustering	

Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I must not cluster
you must not cluster
she 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
she must not be clustering
we must not be clustering
you must not be clustering
they must not be clustering	I must not have clustered
you must not have clustered
she 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
she must not have been clustering
we must not have been clustering
you must not have been clustering
they must not have been clustering	

Forma interrogativa 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
must I cluster?
must you cluster?
must she cluster?
must we cluster?
must you cluster?
must they cluster? 	must I be clustering?
must you be clustering?
must she be clustering?
must we be clustering?
must you be clustering?
must they be clustering? 	must I have clustered?
must you have clustered?
must she 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 she have been clustering?
must we have been clustering?
must you have been clustering?
must they have been clustering? 	

Forma interro-Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
must I not cluster?
must you not cluster?
must she 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 she not be clustering?
must we not be clustering?
must you not be clustering?
must they not be clustering? 	must I not have clustered?
must you not have clustered?
must she 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 she not have been clustering?
must we not have been clustering?
must you not have been clustering?
must they not have been clustering?