could howl
Verbo regular: howl - howled- howled

Afirmação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I could howl
you could howl
he could howl
we could howl
you could howl
they could howl 	I could be howling
you could be howling
he could be howling
we could be howling
you could be howling
they could be howling	I could have howled
you could have howled
he could have howled
we could have howled
you could have howled
they could have howled	I could have been howling
you could have been howling
he could have been howling
we could have been howling
you could have been howling
they could have been howling	

Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I couldn't howl
you couldn't howl
he couldn't howl
we couldn't howl
you couldn't howl
they couldn't howl 	I couldn't be howling
you couldn't be howling
he couldn't be howling
we couldn't be howling
you couldn't be howling
they couldn't be howling	I couldn't have howled
you couldn't have howled
he couldn't have howled
we couldn't have howled
you couldn't have howled
they couldn't have howled	I couldn't have been howling
you couldn't have been howling
he couldn't have been howling
we couldn't have been howling
you couldn't have been howling
they couldn't have been howling	

Forma interrogativa 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
could I howl?
could you howl?
could he howl?
could we howl?
could you howl?
could they howl? 	could I be howling?
could you be howling?
could he be howling?
could we be howling?
could you be howling?
could they be howling? 	could I have howled?
could you have howled?
could he have howled?
could we have howled?
could you have howled?
could they have howled? 	could I have been howling?
could you have been howling?
could he have been howling?
could we have been howling?
could you have been howling?
could they have been howling? 	

Forma interro-Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
couldn't I howl?
couldn't you howl?
couldn't he howl?
couldn't we howl?
couldn't you howl?
couldn't they howl? 	couldn't I be howling?
couldn't you be howling?
couldn't he be howling?
couldn't we be howling?
couldn't you be howling?
couldn't they be howling? 	couldn't I have howled?
couldn't you have howled?
couldn't he have howled?
couldn't we have howled?
couldn't you have howled?
couldn't they have howled? 	couldn't I have been howling?
couldn't you have been howling?
couldn't he have been howling?
couldn't we have been howling?
couldn't you have been howling?
couldn't they have been howling?