English verb conjugation
COULD YAMMER

Regular verb: yammer - yammered - yammered

Affirmation

Simple form	V-ing form
I could yammer you could yammer he could yammer we could yammer you could yammer they could yammer	I could be yammering you could be yammering he could be yammering we could be yammering you could be yammering they could be yammering
Perfect	V-ing perfect
I could have yammered you could have yammered he could have yammered we could have yammered you could have yammered they could have yammered	I could have been yammering you could have been yammering he could have been yammering we could have been yammering you could have been yammering they could have been yammering

Negation

Simple form	V-ing form
I couldn't yammer you couldn't yammer he couldn't yammer we couldn't yammer you couldn't yammer they couldn't yammer	I couldn't be yammering you couldn't be yammering he couldn't be yammering we couldn't be yammering you couldn't be yammering they couldn't be yammering
Perfect	V-ing perfect
I couldn't have yammered you couldn't have yammered he couldn't have yammered we couldn't have yammered you couldn't have yammered they couldn't have yammered	I couldn't have been yammering you couldn't have been yammering he couldn't have been yammering we couldn't have been yammering you couldn't have been yammering they couldn't have been yammering

Interrogative form

Simple form	V-ing form
could I yammer? could you yammer? could he yammer? could we yammer? could you yammer? could they yammer?	could I be yammering? could you be yammering? could he be yammering? could we be yammering? could you be yammering? could they be yammering?
Perfect	V-ing perfect
could I have yammered? could you have yammered? could he have yammered? could we have yammered? could you have yammered? could they have yammered?	could I have been yammering? could you have been yammering? could he have been yammering? could we have been yammering? could you have been yammering? could they have been yammering?

Interro-negative form

Simple form	V-ing form
couldn't I yammer? couldn't you yammer? couldn't he yammer? couldn't we yammer? couldn't you yammer? couldn't they yammer?	couldn't I be yammering? couldn't you be yammering? couldn't he be yammering? couldn't we be yammering? couldn't you be yammering? couldn't they be yammering?
Perfect	V-ing perfect
couldn't I have yammered? couldn't you have yammered? couldn't he have yammered? couldn't we have yammered? couldn't you have yammered? couldn't they have yammered?	couldn't I have been yammering? couldn't you have been yammering? couldn't he have been yammering? couldn't we have been yammering? couldn't you have been yammering? couldn't they have been yammering?