could aid
Regular verb: aid - aided- aided

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could aid
you could aid
he could aid
we could aid
you could aid
they could aid 	I could be aiding
you could be aiding
he could be aiding
we could be aiding
you could be aiding
they could be aiding	I could have aided
you could have aided
he could have aided
we could have aided
you could have aided
they could have aided	I could have been aiding
you could have been aiding
he could have been aiding
we could have been aiding
you could have been aiding
they could have been aiding	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't aid
you couldn't aid
he couldn't aid
we couldn't aid
you couldn't aid
they couldn't aid 	I couldn't be aiding
you couldn't be aiding
he couldn't be aiding
we couldn't be aiding
you couldn't be aiding
they couldn't be aiding	I couldn't have aided
you couldn't have aided
he couldn't have aided
we couldn't have aided
you couldn't have aided
they couldn't have aided	I couldn't have been aiding
you couldn't have been aiding
he couldn't have been aiding
we couldn't have been aiding
you couldn't have been aiding
they couldn't have been aiding	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I aid?
could you aid?
could he aid?
could we aid?
could you aid?
could they aid? 	could I be aiding?
could you be aiding?
could he be aiding?
could we be aiding?
could you be aiding?
could they be aiding? 	could I have aided?
could you have aided?
could he have aided?
could we have aided?
could you have aided?
could they have aided? 	could I have been aiding?
could you have been aiding?
could he have been aiding?
could we have been aiding?
could you have been aiding?
could they have been aiding? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I aid?
couldn't you aid?
couldn't he aid?
couldn't we aid?
couldn't you aid?
couldn't they aid? 	couldn't I be aiding?
couldn't you be aiding?
couldn't he be aiding?
couldn't we be aiding?
couldn't you be aiding?
couldn't they be aiding? 	couldn't I have aided?
couldn't you have aided?
couldn't he have aided?
couldn't we have aided?
couldn't you have aided?
couldn't they have aided? 	couldn't I have been aiding?
couldn't you have been aiding?
couldn't he have been aiding?
couldn't we have been aiding?
couldn't you have been aiding?
couldn't they have been aiding?