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 can't mass
you can't mass
he can't mass
we can't mass
you can't mass
they can't mass 	I can't be massing
you can't be massing
he can't be massing
we can't be massing
you can't be massing
they can't be massing	I can't have massed
you can't have massed
he can't have massed
we can't have massed
you can't have massed
they can't have massed	I can't have been massing
you can't have been massing
he can't have been massing
we can't have been massing
you can't have been massing
they can't 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't I mass?
can't you mass?
can't he mass?
can't we mass?
can't you mass?
can't they mass? 	can't I be massing?
can't you be massing?
can't he be massing?
can't we be massing?
can't you be massing?
can't they be massing? 	can't I have massed?
can't you have massed?
can't he have massed?
can't we have massed?
can't you have massed?
can't they have massed? 	can't I have been massing?
can't you have been massing?
can't he have been massing?
can't we have been massing?
can't you have been massing?
can't they have been massing?