could invalidate
Verbo regular: invalidate - invalidated- invalidated

Afirmação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I could invalidate
you could invalidate
she could invalidate
we could invalidate
you could invalidate
they could invalidate 	I could be invalidating
you could be invalidating
she could be invalidating
we could be invalidating
you could be invalidating
they could be invalidating	I could have invalidated
you could have invalidated
she could have invalidated
we could have invalidated
you could have invalidated
they could have invalidated	I could have been invalidating
you could have been invalidating
she could have been invalidating
we could have been invalidating
you could have been invalidating
they could have been invalidating	

Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I could not invalidate
you could not invalidate
she could not invalidate
we could not invalidate
you could not invalidate
they could not invalidate 	I could not be invalidating
you could not be invalidating
she could not be invalidating
we could not be invalidating
you could not be invalidating
they could not be invalidating	I could not have invalidated
you could not have invalidated
she could not have invalidated
we could not have invalidated
you could not have invalidated
they could not have invalidated	I could not have been invalidating
you could not have been invalidating
she could not have been invalidating
we could not have been invalidating
you could not have been invalidating
they could not have been invalidating	

Forma interrogativa 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
could I invalidate?
could you invalidate?
could she invalidate?
could we invalidate?
could you invalidate?
could they invalidate? 	could I be invalidating?
could you be invalidating?
could she be invalidating?
could we be invalidating?
could you be invalidating?
could they be invalidating? 	could I have invalidated?
could you have invalidated?
could she have invalidated?
could we have invalidated?
could you have invalidated?
could they have invalidated? 	could I have been invalidating?
could you have been invalidating?
could she have been invalidating?
could we have been invalidating?
could you have been invalidating?
could they have been invalidating? 	

Forma interro-Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
could I not invalidate?
could you not invalidate?
could she not invalidate?
could we not invalidate?
could you not invalidate?
could they not invalidate? 	could I not be invalidating?
could you not be invalidating?
could she not be invalidating?
could we not be invalidating?
could you not be invalidating?
could they not be invalidating? 	could I not have invalidated?
could you not have invalidated?
could she not have invalidated?
could we not have invalidated?
could you not have invalidated?
could they not have invalidated? 	could I not have been invalidating?
could you not have been invalidating?
could she not have been invalidating?
could we not have been invalidating?
could you not have been invalidating?
could they not have been invalidating?