English verb conjugation
COULD DRILL

Regular verb: drill - drilled - drilled

Affirmation

Simple form	V-ing form
I could drill you could drill she could drill we could drill you could drill they could drill	I could be drilling you could be drilling she 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 she 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 she 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 she 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 she 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 she 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 she 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 she drill? could we drill? could you drill? could they drill?	could I be drilling? could you be drilling? could she 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 she 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 she 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 she 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 she 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 she 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 she have been drilling? couldn't we have been drilling? couldn't you have been drilling? couldn't they have been drilling?