could systematize
Regular verb: systematize - systematized- systematized

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could systematize
you could systematize
she could systematize
we could systematize
you could systematize
they could systematize 	I could be systematizing
you could be systematizing
she could be systematizing
we could be systematizing
you could be systematizing
they could be systematizing	I could have systematized
you could have systematized
she could have systematized
we could have systematized
you could have systematized
they could have systematized	I could have been systematizing
you could have been systematizing
she could have been systematizing
we could have been systematizing
you could have been systematizing
they could have been systematizing	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't systematize
you couldn't systematize
she couldn't systematize
we couldn't systematize
you couldn't systematize
they couldn't systematize 	I couldn't be systematizing
you couldn't be systematizing
she couldn't be systematizing
we couldn't be systematizing
you couldn't be systematizing
they couldn't be systematizing	I couldn't have systematized
you couldn't have systematized
she couldn't have systematized
we couldn't have systematized
you couldn't have systematized
they couldn't have systematized	I couldn't have been systematizing
you couldn't have been systematizing
she couldn't have been systematizing
we couldn't have been systematizing
you couldn't have been systematizing
they couldn't have been systematizing	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I systematize?
could you systematize?
could she systematize?
could we systematize?
could you systematize?
could they systematize? 	could I be systematizing?
could you be systematizing?
could she be systematizing?
could we be systematizing?
could you be systematizing?
could they be systematizing? 	could I have systematized?
could you have systematized?
could she have systematized?
could we have systematized?
could you have systematized?
could they have systematized? 	could I have been systematizing?
could you have been systematizing?
could she have been systematizing?
could we have been systematizing?
could you have been systematizing?
could they have been systematizing? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I systematize?
couldn't you systematize?
couldn't she systematize?
couldn't we systematize?
couldn't you systematize?
couldn't they systematize? 	couldn't I be systematizing?
couldn't you be systematizing?
couldn't she be systematizing?
couldn't we be systematizing?
couldn't you be systematizing?
couldn't they be systematizing? 	couldn't I have systematized?
couldn't you have systematized?
couldn't she have systematized?
couldn't we have systematized?
couldn't you have systematized?
couldn't they have systematized? 	couldn't I have been systematizing?
couldn't you have been systematizing?
couldn't she have been systematizing?
couldn't we have been systematizing?
couldn't you have been systematizing?
couldn't they have been systematizing?