could plonk
Regular verb: plonk - plonked- plonked

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could plonk
you could plonk
she could plonk
we could plonk
you could plonk
they could plonk 	I could be plonking
you could be plonking
she could be plonking
we could be plonking
you could be plonking
they could be plonking	I could have plonked
you could have plonked
she 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
she 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 could not plonk
you could not plonk
she could not plonk
we could not plonk
you could not plonk
they could not plonk 	I could not be plonking
you could not be plonking
she could not be plonking
we could not be plonking
you could not be plonking
they could not be plonking	I could not have plonked
you could not have plonked
she could not have plonked
we could not have plonked
you could not have plonked
they could not have plonked	I could not have been plonking
you could not have been plonking
she could not have been plonking
we could not have been plonking
you could not have been plonking
they could not have been plonking	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I plonk?
could you plonk?
could she plonk?
could we plonk?
could you plonk?
could they plonk? 	could I be plonking?
could you be plonking?
could she be plonking?
could we be plonking?
could you be plonking?
could they be plonking? 	could I have plonked?
could you have plonked?
could she 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 she 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 	
could I not plonk?
could you not plonk?
could she not plonk?
could we not plonk?
could you not plonk?
could they not plonk? 	could I not be plonking?
could you not be plonking?
could she not be plonking?
could we not be plonking?
could you not be plonking?
could they not be plonking? 	could I not have plonked?
could you not have plonked?
could she not have plonked?
could we not have plonked?
could you not have plonked?
could they not have plonked? 	could I not have been plonking?
could you not have been plonking?
could she not have been plonking?
could we not have been plonking?
could you not have been plonking?
could they not have been plonking?