could factorize
Regular verb: factorize - factorized- factorized

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could factorize
you could factorize
she could factorize
we could factorize
you could factorize
they could factorize 	I could be factorizing
you could be factorizing
she could be factorizing
we could be factorizing
you could be factorizing
they could be factorizing	I could have factorized
you could have factorized
she could have factorized
we could have factorized
you could have factorized
they could have factorized	I could have been factorizing
you could have been factorizing
she could have been factorizing
we could have been factorizing
you could have been factorizing
they could have been factorizing	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't factorize
you couldn't factorize
she couldn't factorize
we couldn't factorize
you couldn't factorize
they couldn't factorize 	I couldn't be factorizing
you couldn't be factorizing
she couldn't be factorizing
we couldn't be factorizing
you couldn't be factorizing
they couldn't be factorizing	I couldn't have factorized
you couldn't have factorized
she couldn't have factorized
we couldn't have factorized
you couldn't have factorized
they couldn't have factorized	I couldn't have been factorizing
you couldn't have been factorizing
she couldn't have been factorizing
we couldn't have been factorizing
you couldn't have been factorizing
they couldn't have been factorizing	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I factorize?
could you factorize?
could she factorize?
could we factorize?
could you factorize?
could they factorize? 	could I be factorizing?
could you be factorizing?
could she be factorizing?
could we be factorizing?
could you be factorizing?
could they be factorizing? 	could I have factorized?
could you have factorized?
could she have factorized?
could we have factorized?
could you have factorized?
could they have factorized? 	could I have been factorizing?
could you have been factorizing?
could she have been factorizing?
could we have been factorizing?
could you have been factorizing?
could they have been factorizing? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I factorize?
couldn't you factorize?
couldn't she factorize?
couldn't we factorize?
couldn't you factorize?
couldn't they factorize? 	couldn't I be factorizing?
couldn't you be factorizing?
couldn't she be factorizing?
couldn't we be factorizing?
couldn't you be factorizing?
couldn't they be factorizing? 	couldn't I have factorized?
couldn't you have factorized?
couldn't she have factorized?
couldn't we have factorized?
couldn't you have factorized?
couldn't they have factorized? 	couldn't I have been factorizing?
couldn't you have been factorizing?
couldn't she have been factorizing?
couldn't we have been factorizing?
couldn't you have been factorizing?
couldn't they have been factorizing?