must accumulate
Regular verb: accumulate - accumulated- accumulated

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must accumulate
you must accumulate
she must accumulate
we must accumulate
you must accumulate
they must accumulate 	I must be accumulating
you must be accumulating
she must be accumulating
we must be accumulating
you must be accumulating
they must be accumulating	I must have accumulated
you must have accumulated
she must have accumulated
we must have accumulated
you must have accumulated
they must have accumulated	I must have been accumulating
you must have been accumulating
she must have been accumulating
we must have been accumulating
you must have been accumulating
they must have been accumulating	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I mustn't accumulate
you mustn't accumulate
she mustn't accumulate
we mustn't accumulate
you mustn't accumulate
they mustn't accumulate 	I mustn't be accumulating
you mustn't be accumulating
she mustn't be accumulating
we mustn't be accumulating
you mustn't be accumulating
they mustn't be accumulating	I mustn't have accumulated
you mustn't have accumulated
she mustn't have accumulated
we mustn't have accumulated
you mustn't have accumulated
they mustn't have accumulated	I mustn't have been accumulating
you mustn't have been accumulating
she mustn't have been accumulating
we mustn't have been accumulating
you mustn't have been accumulating
they mustn't have been accumulating	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I accumulate?
must you accumulate?
must she accumulate?
must we accumulate?
must you accumulate?
must they accumulate? 	must I be accumulating?
must you be accumulating?
must she be accumulating?
must we be accumulating?
must you be accumulating?
must they be accumulating? 	must I have accumulated?
must you have accumulated?
must she have accumulated?
must we have accumulated?
must you have accumulated?
must they have accumulated? 	must I have been accumulating?
must you have been accumulating?
must she have been accumulating?
must we have been accumulating?
must you have been accumulating?
must they have been accumulating? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
mustn't I accumulate?
mustn't you accumulate?
mustn't she accumulate?
mustn't we accumulate?
mustn't you accumulate?
mustn't they accumulate? 	mustn't I be accumulating?
mustn't you be accumulating?
mustn't she be accumulating?
mustn't we be accumulating?
mustn't you be accumulating?
mustn't they be accumulating? 	mustn't I have accumulated?
mustn't you have accumulated?
mustn't she have accumulated?
mustn't we have accumulated?
mustn't you have accumulated?
mustn't they have accumulated? 	mustn't I have been accumulating?
mustn't you have been accumulating?
mustn't she have been accumulating?
mustn't we have been accumulating?
mustn't you have been accumulating?
mustn't they have been accumulating?