could use
Verbo regular: use - used- used

Afirmação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I could use
you could use
she could use
we could use
you could use
they could use 	I could be using
you could be using
she could be using
we could be using
you could be using
they could be using	I could have used
you could have used
she could have used
we could have used
you could have used
they could have used	I could have been using
you could have been using
she could have been using
we could have been using
you could have been using
they could have been using	

Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I couldn't use
you couldn't use
she couldn't use
we couldn't use
you couldn't use
they couldn't use 	I couldn't be using
you couldn't be using
she couldn't be using
we couldn't be using
you couldn't be using
they couldn't be using	I couldn't have used
you couldn't have used
she couldn't have used
we couldn't have used
you couldn't have used
they couldn't have used	I couldn't have been using
you couldn't have been using
she couldn't have been using
we couldn't have been using
you couldn't have been using
they couldn't have been using	

Forma interrogativa 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
could I use?
could you use?
could she use?
could we use?
could you use?
could they use? 	could I be using?
could you be using?
could she be using?
could we be using?
could you be using?
could they be using? 	could I have used?
could you have used?
could she have used?
could we have used?
could you have used?
could they have used? 	could I have been using?
could you have been using?
could she have been using?
could we have been using?
could you have been using?
could they have been using? 	

Forma interro-Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
couldn't I use?
couldn't you use?
couldn't she use?
couldn't we use?
couldn't you use?
couldn't they use? 	couldn't I be using?
couldn't you be using?
couldn't she be using?
couldn't we be using?
couldn't you be using?
couldn't they be using? 	couldn't I have used?
couldn't you have used?
couldn't she have used?
couldn't we have used?
couldn't you have used?
couldn't they have used? 	couldn't I have been using?
couldn't you have been using?
couldn't she have been using?
couldn't we have been using?
couldn't you have been using?
couldn't they have been using?