could trickle
Regular verb: trickle - trickled- trickled

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could trickle
you could trickle
he could trickle
we could trickle
you could trickle
they could trickle 	I could be trickling
you could be trickling
he could be trickling
we could be trickling
you could be trickling
they could be trickling	I could have trickled
you could have trickled
he could have trickled
we could have trickled
you could have trickled
they could have trickled	I could have been trickling
you could have been trickling
he could have been trickling
we could have been trickling
you could have been trickling
they could have been trickling	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't trickle
you couldn't trickle
he couldn't trickle
we couldn't trickle
you couldn't trickle
they couldn't trickle 	I couldn't be trickling
you couldn't be trickling
he couldn't be trickling
we couldn't be trickling
you couldn't be trickling
they couldn't be trickling	I couldn't have trickled
you couldn't have trickled
he couldn't have trickled
we couldn't have trickled
you couldn't have trickled
they couldn't have trickled	I couldn't have been trickling
you couldn't have been trickling
he couldn't have been trickling
we couldn't have been trickling
you couldn't have been trickling
they couldn't have been trickling	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I trickle?
could you trickle?
could he trickle?
could we trickle?
could you trickle?
could they trickle? 	could I be trickling?
could you be trickling?
could he be trickling?
could we be trickling?
could you be trickling?
could they be trickling? 	could I have trickled?
could you have trickled?
could he have trickled?
could we have trickled?
could you have trickled?
could they have trickled? 	could I have been trickling?
could you have been trickling?
could he have been trickling?
could we have been trickling?
could you have been trickling?
could they have been trickling? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I trickle?
couldn't you trickle?
couldn't he trickle?
couldn't we trickle?
couldn't you trickle?
couldn't they trickle? 	couldn't I be trickling?
couldn't you be trickling?
couldn't he be trickling?
couldn't we be trickling?
couldn't you be trickling?
couldn't they be trickling? 	couldn't I have trickled?
couldn't you have trickled?
couldn't he have trickled?
couldn't we have trickled?
couldn't you have trickled?
couldn't they have trickled? 	couldn't I have been trickling?
couldn't you have been trickling?
couldn't he have been trickling?
couldn't we have been trickling?
couldn't you have been trickling?
couldn't they have been trickling?