could oppugn
Regular verb: oppugn - oppugned- oppugned

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could oppugn
you could oppugn
he could oppugn
we could oppugn
you could oppugn
they could oppugn 	I could be oppugning
you could be oppugning
he could be oppugning
we could be oppugning
you could be oppugning
they could be oppugning	I could have oppugned
you could have oppugned
he could have oppugned
we could have oppugned
you could have oppugned
they could have oppugned	I could have been oppugning
you could have been oppugning
he could have been oppugning
we could have been oppugning
you could have been oppugning
they could have been oppugning	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't oppugn
you couldn't oppugn
he couldn't oppugn
we couldn't oppugn
you couldn't oppugn
they couldn't oppugn 	I couldn't be oppugning
you couldn't be oppugning
he couldn't be oppugning
we couldn't be oppugning
you couldn't be oppugning
they couldn't be oppugning	I couldn't have oppugned
you couldn't have oppugned
he couldn't have oppugned
we couldn't have oppugned
you couldn't have oppugned
they couldn't have oppugned	I couldn't have been oppugning
you couldn't have been oppugning
he couldn't have been oppugning
we couldn't have been oppugning
you couldn't have been oppugning
they couldn't have been oppugning	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I oppugn?
could you oppugn?
could he oppugn?
could we oppugn?
could you oppugn?
could they oppugn? 	could I be oppugning?
could you be oppugning?
could he be oppugning?
could we be oppugning?
could you be oppugning?
could they be oppugning? 	could I have oppugned?
could you have oppugned?
could he have oppugned?
could we have oppugned?
could you have oppugned?
could they have oppugned? 	could I have been oppugning?
could you have been oppugning?
could he have been oppugning?
could we have been oppugning?
could you have been oppugning?
could they have been oppugning? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I oppugn?
couldn't you oppugn?
couldn't he oppugn?
couldn't we oppugn?
couldn't you oppugn?
couldn't they oppugn? 	couldn't I be oppugning?
couldn't you be oppugning?
couldn't he be oppugning?
couldn't we be oppugning?
couldn't you be oppugning?
couldn't they be oppugning? 	couldn't I have oppugned?
couldn't you have oppugned?
couldn't he have oppugned?
couldn't we have oppugned?
couldn't you have oppugned?
couldn't they have oppugned? 	couldn't I have been oppugning?
couldn't you have been oppugning?
couldn't he have been oppugning?
couldn't we have been oppugning?
couldn't you have been oppugning?
couldn't they have been oppugning?