could expound
Regular verb: expound - expounded- expounded

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could expound
you could expound
he could expound
we could expound
you could expound
they could expound 	I could be expounding
you could be expounding
he could be expounding
we could be expounding
you could be expounding
they could be expounding	I could have expounded
you could have expounded
he could have expounded
we could have expounded
you could have expounded
they could have expounded	I could have been expounding
you could have been expounding
he could have been expounding
we could have been expounding
you could have been expounding
they could have been expounding	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't expound
you couldn't expound
he couldn't expound
we couldn't expound
you couldn't expound
they couldn't expound 	I couldn't be expounding
you couldn't be expounding
he couldn't be expounding
we couldn't be expounding
you couldn't be expounding
they couldn't be expounding	I couldn't have expounded
you couldn't have expounded
he couldn't have expounded
we couldn't have expounded
you couldn't have expounded
they couldn't have expounded	I couldn't have been expounding
you couldn't have been expounding
he couldn't have been expounding
we couldn't have been expounding
you couldn't have been expounding
they couldn't have been expounding	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I expound?
could you expound?
could he expound?
could we expound?
could you expound?
could they expound? 	could I be expounding?
could you be expounding?
could he be expounding?
could we be expounding?
could you be expounding?
could they be expounding? 	could I have expounded?
could you have expounded?
could he have expounded?
could we have expounded?
could you have expounded?
could they have expounded? 	could I have been expounding?
could you have been expounding?
could he have been expounding?
could we have been expounding?
could you have been expounding?
could they have been expounding? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I expound?
couldn't you expound?
couldn't he expound?
couldn't we expound?
couldn't you expound?
couldn't they expound? 	couldn't I be expounding?
couldn't you be expounding?
couldn't he be expounding?
couldn't we be expounding?
couldn't you be expounding?
couldn't they be expounding? 	couldn't I have expounded?
couldn't you have expounded?
couldn't he have expounded?
couldn't we have expounded?
couldn't you have expounded?
couldn't they have expounded? 	couldn't I have been expounding?
couldn't you have been expounding?
couldn't he have been expounding?
couldn't we have been expounding?
couldn't you have been expounding?
couldn't they have been expounding?