could undersign
Verbo regular: undersign - undersigned- undersigned

Afirmação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I could undersign
you could undersign
he could undersign
we could undersign
you could undersign
they could undersign 	I could be undersigning
you could be undersigning
he could be undersigning
we could be undersigning
you could be undersigning
they could be undersigning	I could have undersigned
you could have undersigned
he 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
he could have been undersigning
we could have been undersigning
you could have been undersigning
they could have been undersigning	

Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I couldn't undersign
you couldn't undersign
he couldn't undersign
we couldn't undersign
you couldn't undersign
they couldn't undersign 	I couldn't be undersigning
you couldn't be undersigning
he couldn't be undersigning
we couldn't be undersigning
you couldn't be undersigning
they couldn't be undersigning	I couldn't have undersigned
you couldn't have undersigned
he couldn't have undersigned
we couldn't have undersigned
you couldn't have undersigned
they couldn't have undersigned	I couldn't have been undersigning
you couldn't have been undersigning
he couldn't have been undersigning
we couldn't have been undersigning
you couldn't have been undersigning
they couldn't have been undersigning	

Forma interrogativa 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
could I undersign?
could you undersign?
could he undersign?
could we undersign?
could you undersign?
could they undersign? 	could I be undersigning?
could you be undersigning?
could he be undersigning?
could we be undersigning?
could you be undersigning?
could they be undersigning? 	could I have undersigned?
could you have undersigned?
could he 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 he have been undersigning?
could we have been undersigning?
could you have been undersigning?
could they have been undersigning? 	

Forma interro-Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
couldn't I undersign?
couldn't you undersign?
couldn't he undersign?
couldn't we undersign?
couldn't you undersign?
couldn't they undersign? 	couldn't I be undersigning?
couldn't you be undersigning?
couldn't he be undersigning?
couldn't we be undersigning?
couldn't you be undersigning?
couldn't they be undersigning? 	couldn't I have undersigned?
couldn't you have undersigned?
couldn't he have undersigned?
couldn't we have undersigned?
couldn't you have undersigned?
couldn't they have undersigned? 	couldn't I have been undersigning?
couldn't you have been undersigning?
couldn't he have been undersigning?
couldn't we have been undersigning?
couldn't you have been undersigning?
couldn't they have been undersigning?