could demark
Regular verb: demark - demarked- demarked

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could demark
you could demark
he could demark
we could demark
you could demark
they could demark 	I could be demarking
you could be demarking
he could be demarking
we could be demarking
you could be demarking
they could be demarking	I could have demarked
you could have demarked
he could have demarked
we could have demarked
you could have demarked
they could have demarked	I could have been demarking
you could have been demarking
he could have been demarking
we could have been demarking
you could have been demarking
they could have been demarking	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't demark
you couldn't demark
he couldn't demark
we couldn't demark
you couldn't demark
they couldn't demark 	I couldn't be demarking
you couldn't be demarking
he couldn't be demarking
we couldn't be demarking
you couldn't be demarking
they couldn't be demarking	I couldn't have demarked
you couldn't have demarked
he couldn't have demarked
we couldn't have demarked
you couldn't have demarked
they couldn't have demarked	I couldn't have been demarking
you couldn't have been demarking
he couldn't have been demarking
we couldn't have been demarking
you couldn't have been demarking
they couldn't have been demarking	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I demark?
could you demark?
could he demark?
could we demark?
could you demark?
could they demark? 	could I be demarking?
could you be demarking?
could he be demarking?
could we be demarking?
could you be demarking?
could they be demarking? 	could I have demarked?
could you have demarked?
could he have demarked?
could we have demarked?
could you have demarked?
could they have demarked? 	could I have been demarking?
could you have been demarking?
could he have been demarking?
could we have been demarking?
could you have been demarking?
could they have been demarking? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I demark?
couldn't you demark?
couldn't he demark?
couldn't we demark?
couldn't you demark?
couldn't they demark? 	couldn't I be demarking?
couldn't you be demarking?
couldn't he be demarking?
couldn't we be demarking?
couldn't you be demarking?
couldn't they be demarking? 	couldn't I have demarked?
couldn't you have demarked?
couldn't he have demarked?
couldn't we have demarked?
couldn't you have demarked?
couldn't they have demarked? 	couldn't I have been demarking?
couldn't you have been demarking?
couldn't he have been demarking?
couldn't we have been demarking?
couldn't you have been demarking?
couldn't they have been demarking?