can mass
Regular verb: mass - massed- massed

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I can mass
you can mass
he can mass
we can mass
you can mass
they can mass 	I can be massing
you can be massing
he can be massing
we can be massing
you can be massing
they can be massing	I can have massed
you can have massed
he can have massed
we can have massed
you can have massed
they can have massed	I can have been massing
you can have been massing
he can have been massing
we can have been massing
you can have been massing
they can have been massing	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I cannot mass
you cannot mass
he cannot mass
we cannot mass
you cannot mass
they cannot mass 	I cannot be massing
you cannot be massing
he cannot be massing
we cannot be massing
you cannot be massing
they cannot be massing	I cannot have massed
you cannot have massed
he cannot have massed
we cannot have massed
you cannot have massed
they cannot have massed	I cannot have been massing
you cannot have been massing
he cannot have been massing
we cannot have been massing
you cannot have been massing
they cannot have been massing	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
can I mass?
can you mass?
can he mass?
can we mass?
can you mass?
can they mass? 	can I be massing?
can you be massing?
can he be massing?
can we be massing?
can you be massing?
can they be massing? 	can I have massed?
can you have massed?
can he have massed?
can we have massed?
can you have massed?
can they have massed? 	can I have been massing?
can you have been massing?
can he have been massing?
can we have been massing?
can you have been massing?
can they have been massing? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
can I not mass?
can you not mass?
can he not mass?
can we not mass?
can you not mass?
can they not mass? 	can I not be massing?
can you not be massing?
can he not be massing?
can we not be massing?
can you not be massing?
can they not be massing? 	can I not have massed?
can you not have massed?
can he not have massed?
can we not have massed?
can you not have massed?
can they not have massed? 	can I not have been massing?
can you not have been massing?
can he not have been massing?
can we not have been massing?
can you not have been massing?
can they not have been massing?