can ruff
Verbo regular: ruff - ruffed- ruffed

Afirmación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I can ruff
you can ruff
he can ruff
we can ruff
you can ruff
they can ruff 	I can be ruffing
you can be ruffing
he can be ruffing
we can be ruffing
you can be ruffing
they can be ruffing	I can have ruffed
you can have ruffed
he can have ruffed
we can have ruffed
you can have ruffed
they can have ruffed	I can have been ruffing
you can have been ruffing
he can have been ruffing
we can have been ruffing
you can have been ruffing
they can have been ruffing	

Negación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I cannot ruff
you cannot ruff
he cannot ruff
we cannot ruff
you cannot ruff
they cannot ruff 	I cannot be ruffing
you cannot be ruffing
he cannot be ruffing
we cannot be ruffing
you cannot be ruffing
they cannot be ruffing	I cannot have ruffed
you cannot have ruffed
he cannot have ruffed
we cannot have ruffed
you cannot have ruffed
they cannot have ruffed	I cannot have been ruffing
you cannot have been ruffing
he cannot have been ruffing
we cannot have been ruffing
you cannot have been ruffing
they cannot have been ruffing	

Forma interrogativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
can I ruff?
can you ruff?
can he ruff?
can we ruff?
can you ruff?
can they ruff? 	can I be ruffing?
can you be ruffing?
can he be ruffing?
can we be ruffing?
can you be ruffing?
can they be ruffing? 	can I have ruffed?
can you have ruffed?
can he have ruffed?
can we have ruffed?
can you have ruffed?
can they have ruffed? 	can I have been ruffing?
can you have been ruffing?
can he have been ruffing?
can we have been ruffing?
can you have been ruffing?
can they have been ruffing? 	

Forma interro-negativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
can I not ruff?
can you not ruff?
can he not ruff?
can we not ruff?
can you not ruff?
can they not ruff? 	can I not be ruffing?
can you not be ruffing?
can he not be ruffing?
can we not be ruffing?
can you not be ruffing?
can they not be ruffing? 	can I not have ruffed?
can you not have ruffed?
can he not have ruffed?
can we not have ruffed?
can you not have ruffed?
can they not have ruffed? 	can I not have been ruffing?
can you not have been ruffing?
can he not have been ruffing?
can we not have been ruffing?
can you not have been ruffing?
can they not have been ruffing?