can chuff
Regular verb: chuff - chuffed- chuffed

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I can chuff
you can chuff
he can chuff
we can chuff
you can chuff
they can chuff 	I can be chuffing
you can be chuffing
he can be chuffing
we can be chuffing
you can be chuffing
they can be chuffing	I can have chuffed
you can have chuffed
he can have chuffed
we can have chuffed
you can have chuffed
they can have chuffed	I can have been chuffing
you can have been chuffing
he can have been chuffing
we can have been chuffing
you can have been chuffing
they can have been chuffing	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I cannot chuff
you cannot chuff
he cannot chuff
we cannot chuff
you cannot chuff
they cannot chuff 	I cannot be chuffing
you cannot be chuffing
he cannot be chuffing
we cannot be chuffing
you cannot be chuffing
they cannot be chuffing	I cannot have chuffed
you cannot have chuffed
he cannot have chuffed
we cannot have chuffed
you cannot have chuffed
they cannot have chuffed	I cannot have been chuffing
you cannot have been chuffing
he cannot have been chuffing
we cannot have been chuffing
you cannot have been chuffing
they cannot have been chuffing	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
can I chuff?
can you chuff?
can he chuff?
can we chuff?
can you chuff?
can they chuff? 	can I be chuffing?
can you be chuffing?
can he be chuffing?
can we be chuffing?
can you be chuffing?
can they be chuffing? 	can I have chuffed?
can you have chuffed?
can he have chuffed?
can we have chuffed?
can you have chuffed?
can they have chuffed? 	can I have been chuffing?
can you have been chuffing?
can he have been chuffing?
can we have been chuffing?
can you have been chuffing?
can they have been chuffing? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
can I not chuff?
can you not chuff?
can he not chuff?
can we not chuff?
can you not chuff?
can they not chuff? 	can I not be chuffing?
can you not be chuffing?
can he not be chuffing?
can we not be chuffing?
can you not be chuffing?
can they not be chuffing? 	can I not have chuffed?
can you not have chuffed?
can he not have chuffed?
can we not have chuffed?
can you not have chuffed?
can they not have chuffed? 	can I not have been chuffing?
can you not have been chuffing?
can he not have been chuffing?
can we not have been chuffing?
can you not have been chuffing?
can they not have been chuffing?