could explain
Verbo regular: explain - explained- explained

Afirmación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I could explain
you could explain
she could explain
we could explain
you could explain
they could explain 	I could be explaining
you could be explaining
she could be explaining
we could be explaining
you could be explaining
they could be explaining	I could have explained
you could have explained
she could have explained
we could have explained
you could have explained
they could have explained	I could have been explaining
you could have been explaining
she could have been explaining
we could have been explaining
you could have been explaining
they could have been explaining	

Negación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I couldn't explain
you couldn't explain
she couldn't explain
we couldn't explain
you couldn't explain
they couldn't explain 	I couldn't be explaining
you couldn't be explaining
she couldn't be explaining
we couldn't be explaining
you couldn't be explaining
they couldn't be explaining	I couldn't have explained
you couldn't have explained
she couldn't have explained
we couldn't have explained
you couldn't have explained
they couldn't have explained	I couldn't have been explaining
you couldn't have been explaining
she couldn't have been explaining
we couldn't have been explaining
you couldn't have been explaining
they couldn't have been explaining	

Forma interrogativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
could I explain?
could you explain?
could she explain?
could we explain?
could you explain?
could they explain? 	could I be explaining?
could you be explaining?
could she be explaining?
could we be explaining?
could you be explaining?
could they be explaining? 	could I have explained?
could you have explained?
could she have explained?
could we have explained?
could you have explained?
could they have explained? 	could I have been explaining?
could you have been explaining?
could she have been explaining?
could we have been explaining?
could you have been explaining?
could they have been explaining? 	

Forma interro-negativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
couldn't I explain?
couldn't you explain?
couldn't she explain?
couldn't we explain?
couldn't you explain?
couldn't they explain? 	couldn't I be explaining?
couldn't you be explaining?
couldn't she be explaining?
couldn't we be explaining?
couldn't you be explaining?
couldn't they be explaining? 	couldn't I have explained?
couldn't you have explained?
couldn't she have explained?
couldn't we have explained?
couldn't you have explained?
couldn't they have explained? 	couldn't I have been explaining?
couldn't you have been explaining?
couldn't she have been explaining?
couldn't we have been explaining?
couldn't you have been explaining?
couldn't they have been explaining?