could illustrate
Regular verb: illustrate - illustrated- illustrated

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could illustrate
you could illustrate
she could illustrate
we could illustrate
you could illustrate
they could illustrate 	I could be illustrating
you could be illustrating
she could be illustrating
we could be illustrating
you could be illustrating
they could be illustrating	I could have illustrated
you could have illustrated
she could have illustrated
we could have illustrated
you could have illustrated
they could have illustrated	I could have been illustrating
you could have been illustrating
she could have been illustrating
we could have been illustrating
you could have been illustrating
they could have been illustrating	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't illustrate
you couldn't illustrate
she couldn't illustrate
we couldn't illustrate
you couldn't illustrate
they couldn't illustrate 	I couldn't be illustrating
you couldn't be illustrating
she couldn't be illustrating
we couldn't be illustrating
you couldn't be illustrating
they couldn't be illustrating	I couldn't have illustrated
you couldn't have illustrated
she couldn't have illustrated
we couldn't have illustrated
you couldn't have illustrated
they couldn't have illustrated	I couldn't have been illustrating
you couldn't have been illustrating
she couldn't have been illustrating
we couldn't have been illustrating
you couldn't have been illustrating
they couldn't have been illustrating	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I illustrate?
could you illustrate?
could she illustrate?
could we illustrate?
could you illustrate?
could they illustrate? 	could I be illustrating?
could you be illustrating?
could she be illustrating?
could we be illustrating?
could you be illustrating?
could they be illustrating? 	could I have illustrated?
could you have illustrated?
could she have illustrated?
could we have illustrated?
could you have illustrated?
could they have illustrated? 	could I have been illustrating?
could you have been illustrating?
could she have been illustrating?
could we have been illustrating?
could you have been illustrating?
could they have been illustrating? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I illustrate?
couldn't you illustrate?
couldn't she illustrate?
couldn't we illustrate?
couldn't you illustrate?
couldn't they illustrate? 	couldn't I be illustrating?
couldn't you be illustrating?
couldn't she be illustrating?
couldn't we be illustrating?
couldn't you be illustrating?
couldn't they be illustrating? 	couldn't I have illustrated?
couldn't you have illustrated?
couldn't she have illustrated?
couldn't we have illustrated?
couldn't you have illustrated?
couldn't they have illustrated? 	couldn't I have been illustrating?
couldn't you have been illustrating?
couldn't she have been illustrating?
couldn't we have been illustrating?
couldn't you have been illustrating?
couldn't they have been illustrating?