English verb conjugation
COULD PLUG

Regular verb: plug - plugged - plugged

Affirmation

Simple form	V-ing form
I could plug you could plug he could plug we could plug you could plug they could plug	I could be plugging you could be plugging he could be plugging we could be plugging you could be plugging they could be plugging
Perfect	V-ing perfect
I could have plugged you could have plugged he could have plugged we could have plugged you could have plugged they could have plugged	I could have been plugging you could have been plugging he could have been plugging we could have been plugging you could have been plugging they could have been plugging

Negation

Simple form	V-ing form
I couldn't plug you couldn't plug he couldn't plug we couldn't plug you couldn't plug they couldn't plug	I couldn't be plugging you couldn't be plugging he couldn't be plugging we couldn't be plugging you couldn't be plugging they couldn't be plugging
Perfect	V-ing perfect
I couldn't have plugged you couldn't have plugged he couldn't have plugged we couldn't have plugged you couldn't have plugged they couldn't have plugged	I couldn't have been plugging you couldn't have been plugging he couldn't have been plugging we couldn't have been plugging you couldn't have been plugging they couldn't have been plugging

Interrogative form

Simple form	V-ing form
could I plug? could you plug? could he plug? could we plug? could you plug? could they plug?	could I be plugging? could you be plugging? could he be plugging? could we be plugging? could you be plugging? could they be plugging?
Perfect	V-ing perfect
could I have plugged? could you have plugged? could he have plugged? could we have plugged? could you have plugged? could they have plugged?	could I have been plugging? could you have been plugging? could he have been plugging? could we have been plugging? could you have been plugging? could they have been plugging?

Interro-negative form

Simple form	V-ing form
couldn't I plug? couldn't you plug? couldn't he plug? couldn't we plug? couldn't you plug? couldn't they plug?	couldn't I be plugging? couldn't you be plugging? couldn't he be plugging? couldn't we be plugging? couldn't you be plugging? couldn't they be plugging?
Perfect	V-ing perfect
couldn't I have plugged? couldn't you have plugged? couldn't he have plugged? couldn't we have plugged? couldn't you have plugged? couldn't they have plugged?	couldn't I have been plugging? couldn't you have been plugging? couldn't he have been plugging? couldn't we have been plugging? couldn't you have been plugging? couldn't they have been plugging?