could undersign
Verbo regular: undersign - undersigned- undersigned

Afirmación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I could undersign
you could undersign
she could undersign
we could undersign
you could undersign
they could undersign 	I could be undersigning
you could be undersigning
she could be undersigning
we could be undersigning
you could be undersigning
they could be undersigning	I could have undersigned
you could have undersigned
she could have undersigned
we could have undersigned
you could have undersigned
they could have undersigned	I could have been undersigning
you could have been undersigning
she could have been undersigning
we could have been undersigning
you could have been undersigning
they could have been undersigning	

Negación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I could not undersign
you could not undersign
she could not undersign
we could not undersign
you could not undersign
they could not undersign 	I could not be undersigning
you could not be undersigning
she could not be undersigning
we could not be undersigning
you could not be undersigning
they could not be undersigning	I could not have undersigned
you could not have undersigned
she could not have undersigned
we could not have undersigned
you could not have undersigned
they could not have undersigned	I could not have been undersigning
you could not have been undersigning
she could not have been undersigning
we could not have been undersigning
you could not have been undersigning
they could not have been undersigning	

Forma interrogativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
could I undersign?
could you undersign?
could she undersign?
could we undersign?
could you undersign?
could they undersign? 	could I be undersigning?
could you be undersigning?
could she be undersigning?
could we be undersigning?
could you be undersigning?
could they be undersigning? 	could I have undersigned?
could you have undersigned?
could she have undersigned?
could we have undersigned?
could you have undersigned?
could they have undersigned? 	could I have been undersigning?
could you have been undersigning?
could she have been undersigning?
could we have been undersigning?
could you have been undersigning?
could they have been undersigning? 	

Forma interro-negativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
could I not undersign?
could you not undersign?
could she not undersign?
could we not undersign?
could you not undersign?
could they not undersign? 	could I not be undersigning?
could you not be undersigning?
could she not be undersigning?
could we not be undersigning?
could you not be undersigning?
could they not be undersigning? 	could I not have undersigned?
could you not have undersigned?
could she not have undersigned?
could we not have undersigned?
could you not have undersigned?
could they not have undersigned? 	could I not have been undersigning?
could you not have been undersigning?
could she not have been undersigning?
could we not have been undersigning?
could you not have been undersigning?
could they not have been undersigning?