could subdivide
Regular verb: subdivide - subdivided- subdivided

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could subdivide
you could subdivide
he could subdivide
we could subdivide
you could subdivide
they could subdivide 	I could be subdividing
you could be subdividing
he could be subdividing
we could be subdividing
you could be subdividing
they could be subdividing	I could have subdivided
you could have subdivided
he could have subdivided
we could have subdivided
you could have subdivided
they could have subdivided	I could have been subdividing
you could have been subdividing
he could have been subdividing
we could have been subdividing
you could have been subdividing
they could have been subdividing	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't subdivide
you couldn't subdivide
he couldn't subdivide
we couldn't subdivide
you couldn't subdivide
they couldn't subdivide 	I couldn't be subdividing
you couldn't be subdividing
he couldn't be subdividing
we couldn't be subdividing
you couldn't be subdividing
they couldn't be subdividing	I couldn't have subdivided
you couldn't have subdivided
he couldn't have subdivided
we couldn't have subdivided
you couldn't have subdivided
they couldn't have subdivided	I couldn't have been subdividing
you couldn't have been subdividing
he couldn't have been subdividing
we couldn't have been subdividing
you couldn't have been subdividing
they couldn't have been subdividing	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I subdivide?
could you subdivide?
could he subdivide?
could we subdivide?
could you subdivide?
could they subdivide? 	could I be subdividing?
could you be subdividing?
could he be subdividing?
could we be subdividing?
could you be subdividing?
could they be subdividing? 	could I have subdivided?
could you have subdivided?
could he have subdivided?
could we have subdivided?
could you have subdivided?
could they have subdivided? 	could I have been subdividing?
could you have been subdividing?
could he have been subdividing?
could we have been subdividing?
could you have been subdividing?
could they have been subdividing? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I subdivide?
couldn't you subdivide?
couldn't he subdivide?
couldn't we subdivide?
couldn't you subdivide?
couldn't they subdivide? 	couldn't I be subdividing?
couldn't you be subdividing?
couldn't he be subdividing?
couldn't we be subdividing?
couldn't you be subdividing?
couldn't they be subdividing? 	couldn't I have subdivided?
couldn't you have subdivided?
couldn't he have subdivided?
couldn't we have subdivided?
couldn't you have subdivided?
couldn't they have subdivided? 	couldn't I have been subdividing?
couldn't you have been subdividing?
couldn't he have been subdividing?
couldn't we have been subdividing?
couldn't you have been subdividing?
couldn't they have been subdividing?