could invalidate
Verbo regolare: invalidate - invalidated- invalidated

Affermazione 	
Forma semplice 	Forma con V-ing 	Perfetto 	Perfetto con V-ing 	
I could invalidate
you could invalidate
he could invalidate
we could invalidate
you could invalidate
they could invalidate 	I could be invalidating
you could be invalidating
he could be invalidating
we could be invalidating
you could be invalidating
they could be invalidating	I could have invalidated
you could have invalidated
he 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
he could have been invalidating
we could have been invalidating
you could have been invalidating
they could have been invalidating	

Negazione 	
Forma semplice 	Forma con V-ing 	Perfetto 	Perfetto con V-ing 	
I couldn't invalidate
you couldn't invalidate
he couldn't invalidate
we couldn't invalidate
you couldn't invalidate
they couldn't invalidate 	I couldn't be invalidating
you couldn't be invalidating
he couldn't be invalidating
we couldn't be invalidating
you couldn't be invalidating
they couldn't be invalidating	I couldn't have invalidated
you couldn't have invalidated
he couldn't have invalidated
we couldn't have invalidated
you couldn't have invalidated
they couldn't have invalidated	I couldn't have been invalidating
you couldn't have been invalidating
he couldn't have been invalidating
we couldn't have been invalidating
you couldn't have been invalidating
they couldn't have been invalidating	

Forma interrogativa 	
Forma semplice 	Forma con V-ing 	Perfetto 	Perfetto con V-ing 	
could I invalidate?
could you invalidate?
could he invalidate?
could we invalidate?
could you invalidate?
could they invalidate? 	could I be invalidating?
could you be invalidating?
could he be invalidating?
could we be invalidating?
could you be invalidating?
could they be invalidating? 	could I have invalidated?
could you have invalidated?
could he 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 he have been invalidating?
could we have been invalidating?
could you have been invalidating?
could they have been invalidating? 	

Forma interro-negativa 	
Forma semplice 	Forma con V-ing 	Perfetto 	Perfetto con V-ing 	
couldn't I invalidate?
couldn't you invalidate?
couldn't he invalidate?
couldn't we invalidate?
couldn't you invalidate?
couldn't they invalidate? 	couldn't I be invalidating?
couldn't you be invalidating?
couldn't he be invalidating?
couldn't we be invalidating?
couldn't you be invalidating?
couldn't they be invalidating? 	couldn't I have invalidated?
couldn't you have invalidated?
couldn't he have invalidated?
couldn't we have invalidated?
couldn't you have invalidated?
couldn't they have invalidated? 	couldn't I have been invalidating?
couldn't you have been invalidating?
couldn't he have been invalidating?
couldn't we have been invalidating?
couldn't you have been invalidating?
couldn't they have been invalidating?