could stratify
Verbo regular: stratify - stratified- stratified

Afirmación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I could stratify
you could stratify
she could stratify
we could stratify
you could stratify
they could stratify 	I could be stratifying
you could be stratifying
she could be stratifying
we could be stratifying
you could be stratifying
they could be stratifying	I could have stratified
you could have stratified
she could have stratified
we could have stratified
you could have stratified
they could have stratified	I could have been stratifying
you could have been stratifying
she could have been stratifying
we could have been stratifying
you could have been stratifying
they could have been stratifying	

Negación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I could not stratify
you could not stratify
she could not stratify
we could not stratify
you could not stratify
they could not stratify 	I could not be stratifying
you could not be stratifying
she could not be stratifying
we could not be stratifying
you could not be stratifying
they could not be stratifying	I could not have stratified
you could not have stratified
she could not have stratified
we could not have stratified
you could not have stratified
they could not have stratified	I could not have been stratifying
you could not have been stratifying
she could not have been stratifying
we could not have been stratifying
you could not have been stratifying
they could not have been stratifying	

Forma interrogativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
could I stratify?
could you stratify?
could she stratify?
could we stratify?
could you stratify?
could they stratify? 	could I be stratifying?
could you be stratifying?
could she be stratifying?
could we be stratifying?
could you be stratifying?
could they be stratifying? 	could I have stratified?
could you have stratified?
could she have stratified?
could we have stratified?
could you have stratified?
could they have stratified? 	could I have been stratifying?
could you have been stratifying?
could she have been stratifying?
could we have been stratifying?
could you have been stratifying?
could they have been stratifying? 	

Forma interro-negativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
could I not stratify?
could you not stratify?
could she not stratify?
could we not stratify?
could you not stratify?
could they not stratify? 	could I not be stratifying?
could you not be stratifying?
could she not be stratifying?
could we not be stratifying?
could you not be stratifying?
could they not be stratifying? 	could I not have stratified?
could you not have stratified?
could she not have stratified?
could we not have stratified?
could you not have stratified?
could they not have stratified? 	could I not have been stratifying?
could you not have been stratifying?
could she not have been stratifying?
could we not have been stratifying?
could you not have been stratifying?
could they not have been stratifying?