could underprop
Regular verb: underprop - underproped- underproped

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could underprop
you could underprop
she could underprop
we could underprop
you could underprop
they could underprop 	I could be underproping
you could be underproping
she could be underproping
we could be underproping
you could be underproping
they could be underproping	I could have underproped
you could have underproped
she could have underproped
we could have underproped
you could have underproped
they could have underproped	I could have been underproping
you could have been underproping
she could have been underproping
we could have been underproping
you could have been underproping
they could have been underproping	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could not underprop
you could not underprop
she could not underprop
we could not underprop
you could not underprop
they could not underprop 	I could not be underproping
you could not be underproping
she could not be underproping
we could not be underproping
you could not be underproping
they could not be underproping	I could not have underproped
you could not have underproped
she could not have underproped
we could not have underproped
you could not have underproped
they could not have underproped	I could not have been underproping
you could not have been underproping
she could not have been underproping
we could not have been underproping
you could not have been underproping
they could not have been underproping	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I underprop?
could you underprop?
could she underprop?
could we underprop?
could you underprop?
could they underprop? 	could I be underproping?
could you be underproping?
could she be underproping?
could we be underproping?
could you be underproping?
could they be underproping? 	could I have underproped?
could you have underproped?
could she have underproped?
could we have underproped?
could you have underproped?
could they have underproped? 	could I have been underproping?
could you have been underproping?
could she have been underproping?
could we have been underproping?
could you have been underproping?
could they have been underproping? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I not underprop?
could you not underprop?
could she not underprop?
could we not underprop?
could you not underprop?
could they not underprop? 	could I not be underproping?
could you not be underproping?
could she not be underproping?
could we not be underproping?
could you not be underproping?
could they not be underproping? 	could I not have underproped?
could you not have underproped?
could she not have underproped?
could we not have underproped?
could you not have underproped?
could they not have underproped? 	could I not have been underproping?
could you not have been underproping?
could she not have been underproping?
could we not have been underproping?
could you not have been underproping?
could they not have been underproping?