English verb conjugation
COULD PLOUGH

Regular verb: plough - ploughed - ploughed

Affirmation

Simple form	V-ing form
I could plough you could plough he could plough we could plough you could plough they could plough	I could be ploughing you could be ploughing he could be ploughing we could be ploughing you could be ploughing they could be ploughing
Perfect	V-ing perfect
I could have ploughed you could have ploughed he could have ploughed we could have ploughed you could have ploughed they could have ploughed	I could have been ploughing you could have been ploughing he could have been ploughing we could have been ploughing you could have been ploughing they could have been ploughing

Negation

Simple form	V-ing form
I couldn't plough you couldn't plough he couldn't plough we couldn't plough you couldn't plough they couldn't plough	I couldn't be ploughing you couldn't be ploughing he couldn't be ploughing we couldn't be ploughing you couldn't be ploughing they couldn't be ploughing
Perfect	V-ing perfect
I couldn't have ploughed you couldn't have ploughed he couldn't have ploughed we couldn't have ploughed you couldn't have ploughed they couldn't have ploughed	I couldn't have been ploughing you couldn't have been ploughing he couldn't have been ploughing we couldn't have been ploughing you couldn't have been ploughing they couldn't have been ploughing

Interrogative form

Simple form	V-ing form
could I plough? could you plough? could he plough? could we plough? could you plough? could they plough?	could I be ploughing? could you be ploughing? could he be ploughing? could we be ploughing? could you be ploughing? could they be ploughing?
Perfect	V-ing perfect
could I have ploughed? could you have ploughed? could he have ploughed? could we have ploughed? could you have ploughed? could they have ploughed?	could I have been ploughing? could you have been ploughing? could he have been ploughing? could we have been ploughing? could you have been ploughing? could they have been ploughing?

Interro-negative form

Simple form	V-ing form
couldn't I plough? couldn't you plough? couldn't he plough? couldn't we plough? couldn't you plough? couldn't they plough?	couldn't I be ploughing? couldn't you be ploughing? couldn't he be ploughing? couldn't we be ploughing? couldn't you be ploughing? couldn't they be ploughing?
Perfect	V-ing perfect
couldn't I have ploughed? couldn't you have ploughed? couldn't he have ploughed? couldn't we have ploughed? couldn't you have ploughed? couldn't they have ploughed?	couldn't I have been ploughing? couldn't you have been ploughing? couldn't he have been ploughing? couldn't we have been ploughing? couldn't you have been ploughing? couldn't they have been ploughing?