could rivet
Regular verb: rivet - riveted- riveted

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could rivet
you could rivet
he could rivet
we could rivet
you could rivet
they could rivet 	I could be riveting
you could be riveting
he could be riveting
we could be riveting
you could be riveting
they could be riveting	I could have riveted
you could have riveted
he could have riveted
we could have riveted
you could have riveted
they could have riveted	I could have been riveting
you could have been riveting
he could have been riveting
we could have been riveting
you could have been riveting
they could have been riveting	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't rivet
you couldn't rivet
he couldn't rivet
we couldn't rivet
you couldn't rivet
they couldn't rivet 	I couldn't be riveting
you couldn't be riveting
he couldn't be riveting
we couldn't be riveting
you couldn't be riveting
they couldn't be riveting	I couldn't have riveted
you couldn't have riveted
he couldn't have riveted
we couldn't have riveted
you couldn't have riveted
they couldn't have riveted	I couldn't have been riveting
you couldn't have been riveting
he couldn't have been riveting
we couldn't have been riveting
you couldn't have been riveting
they couldn't have been riveting	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I rivet?
could you rivet?
could he rivet?
could we rivet?
could you rivet?
could they rivet? 	could I be riveting?
could you be riveting?
could he be riveting?
could we be riveting?
could you be riveting?
could they be riveting? 	could I have riveted?
could you have riveted?
could he have riveted?
could we have riveted?
could you have riveted?
could they have riveted? 	could I have been riveting?
could you have been riveting?
could he have been riveting?
could we have been riveting?
could you have been riveting?
could they have been riveting? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I rivet?
couldn't you rivet?
couldn't he rivet?
couldn't we rivet?
couldn't you rivet?
couldn't they rivet? 	couldn't I be riveting?
couldn't you be riveting?
couldn't he be riveting?
couldn't we be riveting?
couldn't you be riveting?
couldn't they be riveting? 	couldn't I have riveted?
couldn't you have riveted?
couldn't he have riveted?
couldn't we have riveted?
couldn't you have riveted?
couldn't they have riveted? 	couldn't I have been riveting?
couldn't you have been riveting?
couldn't he have been riveting?
couldn't we have been riveting?
couldn't you have been riveting?
couldn't they have been riveting?