could naturalize
Regular verb: naturalize - naturalized- naturalized

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could naturalize
you could naturalize
he could naturalize
we could naturalize
you could naturalize
they could naturalize 	I could be naturalizing
you could be naturalizing
he could be naturalizing
we could be naturalizing
you could be naturalizing
they could be naturalizing	I could have naturalized
you could have naturalized
he could have naturalized
we could have naturalized
you could have naturalized
they could have naturalized	I could have been naturalizing
you could have been naturalizing
he could have been naturalizing
we could have been naturalizing
you could have been naturalizing
they could have been naturalizing	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could not naturalize
you could not naturalize
he could not naturalize
we could not naturalize
you could not naturalize
they could not naturalize 	I could not be naturalizing
you could not be naturalizing
he could not be naturalizing
we could not be naturalizing
you could not be naturalizing
they could not be naturalizing	I could not have naturalized
you could not have naturalized
he could not have naturalized
we could not have naturalized
you could not have naturalized
they could not have naturalized	I could not have been naturalizing
you could not have been naturalizing
he could not have been naturalizing
we could not have been naturalizing
you could not have been naturalizing
they could not have been naturalizing	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I naturalize?
could you naturalize?
could he naturalize?
could we naturalize?
could you naturalize?
could they naturalize? 	could I be naturalizing?
could you be naturalizing?
could he be naturalizing?
could we be naturalizing?
could you be naturalizing?
could they be naturalizing? 	could I have naturalized?
could you have naturalized?
could he have naturalized?
could we have naturalized?
could you have naturalized?
could they have naturalized? 	could I have been naturalizing?
could you have been naturalizing?
could he have been naturalizing?
could we have been naturalizing?
could you have been naturalizing?
could they have been naturalizing? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I not naturalize?
could you not naturalize?
could he not naturalize?
could we not naturalize?
could you not naturalize?
could they not naturalize? 	could I not be naturalizing?
could you not be naturalizing?
could he not be naturalizing?
could we not be naturalizing?
could you not be naturalizing?
could they not be naturalizing? 	could I not have naturalized?
could you not have naturalized?
could he not have naturalized?
could we not have naturalized?
could you not have naturalized?
could they not have naturalized? 	could I not have been naturalizing?
could you not have been naturalizing?
could he not have been naturalizing?
could we not have been naturalizing?
could you not have been naturalizing?
could they not have been naturalizing?