could clank
Regular verb: clank - clanked- clanked

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could clank
you could clank
she could clank
we could clank
you could clank
they could clank 	I could be clanking
you could be clanking
she could be clanking
we could be clanking
you could be clanking
they could be clanking	I could have clanked
you could have clanked
she 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
she 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 could not clank
you could not clank
she could not clank
we could not clank
you could not clank
they could not clank 	I could not be clanking
you could not be clanking
she could not be clanking
we could not be clanking
you could not be clanking
they could not be clanking	I could not have clanked
you could not have clanked
she could not have clanked
we could not have clanked
you could not have clanked
they could not have clanked	I could not have been clanking
you could not have been clanking
she could not have been clanking
we could not have been clanking
you could not have been clanking
they could not have been clanking	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I clank?
could you clank?
could she clank?
could we clank?
could you clank?
could they clank? 	could I be clanking?
could you be clanking?
could she be clanking?
could we be clanking?
could you be clanking?
could they be clanking? 	could I have clanked?
could you have clanked?
could she 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 she 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 	
could I not clank?
could you not clank?
could she not clank?
could we not clank?
could you not clank?
could they not clank? 	could I not be clanking?
could you not be clanking?
could she not be clanking?
could we not be clanking?
could you not be clanking?
could they not be clanking? 	could I not have clanked?
could you not have clanked?
could she not have clanked?
could we not have clanked?
could you not have clanked?
could they not have clanked? 	could I not have been clanking?
could you not have been clanking?
could she not have been clanking?
could we not have been clanking?
could you not have been clanking?
could they not have been clanking?