English verb conjugation
COULD DRILL

Regular verb: drill - drilled - drilled

Affirmation

Simple form	V-ing form
I could drill you could drill he could drill we could drill you could drill they could drill	I could be drilling you could be drilling he could be drilling we could be drilling you could be drilling they could be drilling
Perfect	V-ing perfect
I could have drilled you could have drilled he could have drilled we could have drilled you could have drilled they could have drilled	I could have been drilling you could have been drilling he could have been drilling we could have been drilling you could have been drilling they could have been drilling

Negation

Simple form	V-ing form
I couldn't drill you couldn't drill he couldn't drill we couldn't drill you couldn't drill they couldn't drill	I couldn't be drilling you couldn't be drilling he couldn't be drilling we couldn't be drilling you couldn't be drilling they couldn't be drilling
Perfect	V-ing perfect
I couldn't have drilled you couldn't have drilled he couldn't have drilled we couldn't have drilled you couldn't have drilled they couldn't have drilled	I couldn't have been drilling you couldn't have been drilling he couldn't have been drilling we couldn't have been drilling you couldn't have been drilling they couldn't have been drilling

Interrogative form

Simple form	V-ing form
could I drill? could you drill? could he drill? could we drill? could you drill? could they drill?	could I be drilling? could you be drilling? could he be drilling? could we be drilling? could you be drilling? could they be drilling?
Perfect	V-ing perfect
could I have drilled? could you have drilled? could he have drilled? could we have drilled? could you have drilled? could they have drilled?	could I have been drilling? could you have been drilling? could he have been drilling? could we have been drilling? could you have been drilling? could they have been drilling?

Interro-negative form

Simple form	V-ing form
couldn't I drill? couldn't you drill? couldn't he drill? couldn't we drill? couldn't you drill? couldn't they drill?	couldn't I be drilling? couldn't you be drilling? couldn't he be drilling? couldn't we be drilling? couldn't you be drilling? couldn't they be drilling?
Perfect	V-ing perfect
couldn't I have drilled? couldn't you have drilled? couldn't he have drilled? couldn't we have drilled? couldn't you have drilled? couldn't they have drilled?	couldn't I have been drilling? couldn't you have been drilling? couldn't he have been drilling? couldn't we have been drilling? couldn't you have been drilling? couldn't they have been drilling?