could clank
Regular verb: clank - clanked- clanked

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could clank
you could clank
he could clank
we could clank
you could clank
they could clank 	I could be clanking
you could be clanking
he could be clanking
we could be clanking
you could be clanking
they could be clanking	I could have clanked
you could have clanked
he could have clanked
we could have clanked
you could have clanked
they could have clanked	I could have been clanking
you could have been clanking
he could have been clanking
we could have been clanking
you could have been clanking
they could have been clanking	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't clank
you couldn't clank
he couldn't clank
we couldn't clank
you couldn't clank
they couldn't clank 	I couldn't be clanking
you couldn't be clanking
he couldn't be clanking
we couldn't be clanking
you couldn't be clanking
they couldn't be clanking	I couldn't have clanked
you couldn't have clanked
he couldn't have clanked
we couldn't have clanked
you couldn't have clanked
they couldn't have clanked	I couldn't have been clanking
you couldn't have been clanking
he couldn't have been clanking
we couldn't have been clanking
you couldn't have been clanking
they couldn't have been clanking	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I clank?
could you clank?
could he clank?
could we clank?
could you clank?
could they clank? 	could I be clanking?
could you be clanking?
could he be clanking?
could we be clanking?
could you be clanking?
could they be clanking? 	could I have clanked?
could you have clanked?
could he have clanked?
could we have clanked?
could you have clanked?
could they have clanked? 	could I have been clanking?
could you have been clanking?
could he have been clanking?
could we have been clanking?
could you have been clanking?
could they have been clanking? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I clank?
couldn't you clank?
couldn't he clank?
couldn't we clank?
couldn't you clank?
couldn't they clank? 	couldn't I be clanking?
couldn't you be clanking?
couldn't he be clanking?
couldn't we be clanking?
couldn't you be clanking?
couldn't they be clanking? 	couldn't I have clanked?
couldn't you have clanked?
couldn't he have clanked?
couldn't we have clanked?
couldn't you have clanked?
couldn't they have clanked? 	couldn't I have been clanking?
couldn't you have been clanking?
couldn't he have been clanking?
couldn't we have been clanking?
couldn't you have been clanking?
couldn't they have been clanking?