could prop
Regular verb: prop - propped- propped

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could prop
you could prop
he could prop
we could prop
you could prop
they could prop 	I could be propping
you could be propping
he could be propping
we could be propping
you could be propping
they could be propping	I could have propped
you could have propped
he could have propped
we could have propped
you could have propped
they could have propped	I could have been propping
you could have been propping
he could have been propping
we could have been propping
you could have been propping
they could have been propping	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't prop
you couldn't prop
he couldn't prop
we couldn't prop
you couldn't prop
they couldn't prop 	I couldn't be propping
you couldn't be propping
he couldn't be propping
we couldn't be propping
you couldn't be propping
they couldn't be propping	I couldn't have propped
you couldn't have propped
he couldn't have propped
we couldn't have propped
you couldn't have propped
they couldn't have propped	I couldn't have been propping
you couldn't have been propping
he couldn't have been propping
we couldn't have been propping
you couldn't have been propping
they couldn't have been propping	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I prop?
could you prop?
could he prop?
could we prop?
could you prop?
could they prop? 	could I be propping?
could you be propping?
could he be propping?
could we be propping?
could you be propping?
could they be propping? 	could I have propped?
could you have propped?
could he have propped?
could we have propped?
could you have propped?
could they have propped? 	could I have been propping?
could you have been propping?
could he have been propping?
could we have been propping?
could you have been propping?
could they have been propping? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I prop?
couldn't you prop?
couldn't he prop?
couldn't we prop?
couldn't you prop?
couldn't they prop? 	couldn't I be propping?
couldn't you be propping?
couldn't he be propping?
couldn't we be propping?
couldn't you be propping?
couldn't they be propping? 	couldn't I have propped?
couldn't you have propped?
couldn't he have propped?
couldn't we have propped?
couldn't you have propped?
couldn't they have propped? 	couldn't I have been propping?
couldn't you have been propping?
couldn't he have been propping?
couldn't we have been propping?
couldn't you have been propping?
couldn't they have been propping?