could underline
Regular verb: underline - underlined- underlined

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could underline
you could underline
she could underline
we could underline
you could underline
they could underline 	I could be underlining
you could be underlining
she could be underlining
we could be underlining
you could be underlining
they could be underlining	I could have underlined
you could have underlined
she could have underlined
we could have underlined
you could have underlined
they could have underlined	I could have been underlining
you could have been underlining
she could have been underlining
we could have been underlining
you could have been underlining
they could have been underlining	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could not underline
you could not underline
she could not underline
we could not underline
you could not underline
they could not underline 	I could not be underlining
you could not be underlining
she could not be underlining
we could not be underlining
you could not be underlining
they could not be underlining	I could not have underlined
you could not have underlined
she could not have underlined
we could not have underlined
you could not have underlined
they could not have underlined	I could not have been underlining
you could not have been underlining
she could not have been underlining
we could not have been underlining
you could not have been underlining
they could not have been underlining	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I underline?
could you underline?
could she underline?
could we underline?
could you underline?
could they underline? 	could I be underlining?
could you be underlining?
could she be underlining?
could we be underlining?
could you be underlining?
could they be underlining? 	could I have underlined?
could you have underlined?
could she have underlined?
could we have underlined?
could you have underlined?
could they have underlined? 	could I have been underlining?
could you have been underlining?
could she have been underlining?
could we have been underlining?
could you have been underlining?
could they have been underlining? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I not underline?
could you not underline?
could she not underline?
could we not underline?
could you not underline?
could they not underline? 	could I not be underlining?
could you not be underlining?
could she not be underlining?
could we not be underlining?
could you not be underlining?
could they not be underlining? 	could I not have underlined?
could you not have underlined?
could she not have underlined?
could we not have underlined?
could you not have underlined?
could they not have underlined? 	could I not have been underlining?
could you not have been underlining?
could she not have been underlining?
could we not have been underlining?
could you not have been underlining?
could they not have been underlining?