could study
Verbo regular: study - studied- studied

Afirmação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I could study
you could study
she could study
we could study
you could study
they could study 	I could be studying
you could be studying
she could be studying
we could be studying
you could be studying
they could be studying	I could have studied
you could have studied
she could have studied
we could have studied
you could have studied
they could have studied	I could have been studying
you could have been studying
she could have been studying
we could have been studying
you could have been studying
they could have been studying	

Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I couldn't study
you couldn't study
she couldn't study
we couldn't study
you couldn't study
they couldn't study 	I couldn't be studying
you couldn't be studying
she couldn't be studying
we couldn't be studying
you couldn't be studying
they couldn't be studying	I couldn't have studied
you couldn't have studied
she couldn't have studied
we couldn't have studied
you couldn't have studied
they couldn't have studied	I couldn't have been studying
you couldn't have been studying
she couldn't have been studying
we couldn't have been studying
you couldn't have been studying
they couldn't have been studying	

Forma interrogativa 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
could I study?
could you study?
could she study?
could we study?
could you study?
could they study? 	could I be studying?
could you be studying?
could she be studying?
could we be studying?
could you be studying?
could they be studying? 	could I have studied?
could you have studied?
could she have studied?
could we have studied?
could you have studied?
could they have studied? 	could I have been studying?
could you have been studying?
could she have been studying?
could we have been studying?
could you have been studying?
could they have been studying? 	

Forma interro-Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
couldn't I study?
couldn't you study?
couldn't she study?
couldn't we study?
couldn't you study?
couldn't they study? 	couldn't I be studying?
couldn't you be studying?
couldn't she be studying?
couldn't we be studying?
couldn't you be studying?
couldn't they be studying? 	couldn't I have studied?
couldn't you have studied?
couldn't she have studied?
couldn't we have studied?
couldn't you have studied?
couldn't they have studied? 	couldn't I have been studying?
couldn't you have been studying?
couldn't she have been studying?
couldn't we have been studying?
couldn't you have been studying?
couldn't they have been studying?