English verb conjugation
COULD FURROW

Regular verb: furrow - furrowed - furrowed

Affirmation

Simple form	V-ing form
I could furrow you could furrow he could furrow we could furrow you could furrow they could furrow	I could be furrowing you could be furrowing he could be furrowing we could be furrowing you could be furrowing they could be furrowing
Perfect	V-ing perfect
I could have furrowed you could have furrowed he could have furrowed we could have furrowed you could have furrowed they could have furrowed	I could have been furrowing you could have been furrowing he could have been furrowing we could have been furrowing you could have been furrowing they could have been furrowing

Negation

Simple form	V-ing form
I couldn't furrow you couldn't furrow he couldn't furrow we couldn't furrow you couldn't furrow they couldn't furrow	I couldn't be furrowing you couldn't be furrowing he couldn't be furrowing we couldn't be furrowing you couldn't be furrowing they couldn't be furrowing
Perfect	V-ing perfect
I couldn't have furrowed you couldn't have furrowed he couldn't have furrowed we couldn't have furrowed you couldn't have furrowed they couldn't have furrowed	I couldn't have been furrowing you couldn't have been furrowing he couldn't have been furrowing we couldn't have been furrowing you couldn't have been furrowing they couldn't have been furrowing

Interrogative form

Simple form	V-ing form
could I furrow? could you furrow? could he furrow? could we furrow? could you furrow? could they furrow?	could I be furrowing? could you be furrowing? could he be furrowing? could we be furrowing? could you be furrowing? could they be furrowing?
Perfect	V-ing perfect
could I have furrowed? could you have furrowed? could he have furrowed? could we have furrowed? could you have furrowed? could they have furrowed?	could I have been furrowing? could you have been furrowing? could he have been furrowing? could we have been furrowing? could you have been furrowing? could they have been furrowing?

Interro-negative form

Simple form	V-ing form
couldn't I furrow? couldn't you furrow? couldn't he furrow? couldn't we furrow? couldn't you furrow? couldn't they furrow?	couldn't I be furrowing? couldn't you be furrowing? couldn't he be furrowing? couldn't we be furrowing? couldn't you be furrowing? couldn't they be furrowing?
Perfect	V-ing perfect
couldn't I have furrowed? couldn't you have furrowed? couldn't he have furrowed? couldn't we have furrowed? couldn't you have furrowed? couldn't they have furrowed?	couldn't I have been furrowing? couldn't you have been furrowing? couldn't he have been furrowing? couldn't we have been furrowing? couldn't you have been furrowing? couldn't they have been furrowing?