could improve
Verbo regular: improve - improved- improved

Afirmación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I could improve
you could improve
he could improve
we could improve
you could improve
they could improve 	I could be improving
you could be improving
he could be improving
we could be improving
you could be improving
they could be improving	I could have improved
you could have improved
he could have improved
we could have improved
you could have improved
they could have improved	I could have been improving
you could have been improving
he could have been improving
we could have been improving
you could have been improving
they could have been improving	

Negación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I couldn't improve
you couldn't improve
he couldn't improve
we couldn't improve
you couldn't improve
they couldn't improve 	I couldn't be improving
you couldn't be improving
he couldn't be improving
we couldn't be improving
you couldn't be improving
they couldn't be improving	I couldn't have improved
you couldn't have improved
he couldn't have improved
we couldn't have improved
you couldn't have improved
they couldn't have improved	I couldn't have been improving
you couldn't have been improving
he couldn't have been improving
we couldn't have been improving
you couldn't have been improving
they couldn't have been improving	

Forma interrogativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
could I improve?
could you improve?
could he improve?
could we improve?
could you improve?
could they improve? 	could I be improving?
could you be improving?
could he be improving?
could we be improving?
could you be improving?
could they be improving? 	could I have improved?
could you have improved?
could he have improved?
could we have improved?
could you have improved?
could they have improved? 	could I have been improving?
could you have been improving?
could he have been improving?
could we have been improving?
could you have been improving?
could they have been improving? 	

Forma interro-negativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
couldn't I improve?
couldn't you improve?
couldn't he improve?
couldn't we improve?
couldn't you improve?
couldn't they improve? 	couldn't I be improving?
couldn't you be improving?
couldn't he be improving?
couldn't we be improving?
couldn't you be improving?
couldn't they be improving? 	couldn't I have improved?
couldn't you have improved?
couldn't he have improved?
couldn't we have improved?
couldn't you have improved?
couldn't they have improved? 	couldn't I have been improving?
couldn't you have been improving?
couldn't he have been improving?
couldn't we have been improving?
couldn't you have been improving?
couldn't they have been improving?