could flank
Regular verb: flank - flanked- flanked

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could flank
you could flank
she could flank
we could flank
you could flank
they could flank 	I could be flanking
you could be flanking
she could be flanking
we could be flanking
you could be flanking
they could be flanking	I could have flanked
you could have flanked
she could have flanked
we could have flanked
you could have flanked
they could have flanked	I could have been flanking
you could have been flanking
she could have been flanking
we could have been flanking
you could have been flanking
they could have been flanking	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't flank
you couldn't flank
she couldn't flank
we couldn't flank
you couldn't flank
they couldn't flank 	I couldn't be flanking
you couldn't be flanking
she couldn't be flanking
we couldn't be flanking
you couldn't be flanking
they couldn't be flanking	I couldn't have flanked
you couldn't have flanked
she couldn't have flanked
we couldn't have flanked
you couldn't have flanked
they couldn't have flanked	I couldn't have been flanking
you couldn't have been flanking
she couldn't have been flanking
we couldn't have been flanking
you couldn't have been flanking
they couldn't have been flanking	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I flank?
could you flank?
could she flank?
could we flank?
could you flank?
could they flank? 	could I be flanking?
could you be flanking?
could she be flanking?
could we be flanking?
could you be flanking?
could they be flanking? 	could I have flanked?
could you have flanked?
could she have flanked?
could we have flanked?
could you have flanked?
could they have flanked? 	could I have been flanking?
could you have been flanking?
could she have been flanking?
could we have been flanking?
could you have been flanking?
could they have been flanking? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I flank?
couldn't you flank?
couldn't she flank?
couldn't we flank?
couldn't you flank?
couldn't they flank? 	couldn't I be flanking?
couldn't you be flanking?
couldn't she be flanking?
couldn't we be flanking?
couldn't you be flanking?
couldn't they be flanking? 	couldn't I have flanked?
couldn't you have flanked?
couldn't she have flanked?
couldn't we have flanked?
couldn't you have flanked?
couldn't they have flanked? 	couldn't I have been flanking?
couldn't you have been flanking?
couldn't she have been flanking?
couldn't we have been flanking?
couldn't you have been flanking?
couldn't they have been flanking?