could plonk
Regular verb: plonk - plonked- plonked

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could plonk
you could plonk
he could plonk
we could plonk
you could plonk
they could plonk 	I could be plonking
you could be plonking
he could be plonking
we could be plonking
you could be plonking
they could be plonking	I could have plonked
you could have plonked
he could have plonked
we could have plonked
you could have plonked
they could have plonked	I could have been plonking
you could have been plonking
he could have been plonking
we could have been plonking
you could have been plonking
they could have been plonking	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't plonk
you couldn't plonk
he couldn't plonk
we couldn't plonk
you couldn't plonk
they couldn't plonk 	I couldn't be plonking
you couldn't be plonking
he couldn't be plonking
we couldn't be plonking
you couldn't be plonking
they couldn't be plonking	I couldn't have plonked
you couldn't have plonked
he couldn't have plonked
we couldn't have plonked
you couldn't have plonked
they couldn't have plonked	I couldn't have been plonking
you couldn't have been plonking
he couldn't have been plonking
we couldn't have been plonking
you couldn't have been plonking
they couldn't have been plonking	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I plonk?
could you plonk?
could he plonk?
could we plonk?
could you plonk?
could they plonk? 	could I be plonking?
could you be plonking?
could he be plonking?
could we be plonking?
could you be plonking?
could they be plonking? 	could I have plonked?
could you have plonked?
could he have plonked?
could we have plonked?
could you have plonked?
could they have plonked? 	could I have been plonking?
could you have been plonking?
could he have been plonking?
could we have been plonking?
could you have been plonking?
could they have been plonking? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I plonk?
couldn't you plonk?
couldn't he plonk?
couldn't we plonk?
couldn't you plonk?
couldn't they plonk? 	couldn't I be plonking?
couldn't you be plonking?
couldn't he be plonking?
couldn't we be plonking?
couldn't you be plonking?
couldn't they be plonking? 	couldn't I have plonked?
couldn't you have plonked?
couldn't he have plonked?
couldn't we have plonked?
couldn't you have plonked?
couldn't they have plonked? 	couldn't I have been plonking?
couldn't you have been plonking?
couldn't he have been plonking?
couldn't we have been plonking?
couldn't you have been plonking?
couldn't they have been plonking?