could preserve
Verbo regular: preserve - preserved- preserved

Afirmación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I could preserve
you could preserve
she could preserve
we could preserve
you could preserve
they could preserve 	I could be preserving
you could be preserving
she could be preserving
we could be preserving
you could be preserving
they could be preserving	I could have preserved
you could have preserved
she could have preserved
we could have preserved
you could have preserved
they could have preserved	I could have been preserving
you could have been preserving
she could have been preserving
we could have been preserving
you could have been preserving
they could have been preserving	

Negación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I could not preserve
you could not preserve
she could not preserve
we could not preserve
you could not preserve
they could not preserve 	I could not be preserving
you could not be preserving
she could not be preserving
we could not be preserving
you could not be preserving
they could not be preserving	I could not have preserved
you could not have preserved
she could not have preserved
we could not have preserved
you could not have preserved
they could not have preserved	I could not have been preserving
you could not have been preserving
she could not have been preserving
we could not have been preserving
you could not have been preserving
they could not have been preserving	

Forma interrogativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
could I preserve?
could you preserve?
could she preserve?
could we preserve?
could you preserve?
could they preserve? 	could I be preserving?
could you be preserving?
could she be preserving?
could we be preserving?
could you be preserving?
could they be preserving? 	could I have preserved?
could you have preserved?
could she have preserved?
could we have preserved?
could you have preserved?
could they have preserved? 	could I have been preserving?
could you have been preserving?
could she have been preserving?
could we have been preserving?
could you have been preserving?
could they have been preserving? 	

Forma interro-negativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
could I not preserve?
could you not preserve?
could she not preserve?
could we not preserve?
could you not preserve?
could they not preserve? 	could I not be preserving?
could you not be preserving?
could she not be preserving?
could we not be preserving?
could you not be preserving?
could they not be preserving? 	could I not have preserved?
could you not have preserved?
could she not have preserved?
could we not have preserved?
could you not have preserved?
could they not have preserved? 	could I not have been preserving?
could you not have been preserving?
could she not have been preserving?
could we not have been preserving?
could you not have been preserving?
could they not have been preserving?