English verb conjugation
COULD HEFT

Regular verb: heft - hefted - hefted

Affirmation

Simple form	V-ing form
I could heft you could heft he could heft we could heft you could heft they could heft	I could be hefting you could be hefting he could be hefting we could be hefting you could be hefting they could be hefting
Perfect	V-ing perfect
I could have hefted you could have hefted he could have hefted we could have hefted you could have hefted they could have hefted	I could have been hefting you could have been hefting he could have been hefting we could have been hefting you could have been hefting they could have been hefting

Negation

Simple form	V-ing form
I couldn't heft you couldn't heft he couldn't heft we couldn't heft you couldn't heft they couldn't heft	I couldn't be hefting you couldn't be hefting he couldn't be hefting we couldn't be hefting you couldn't be hefting they couldn't be hefting
Perfect	V-ing perfect
I couldn't have hefted you couldn't have hefted he couldn't have hefted we couldn't have hefted you couldn't have hefted they couldn't have hefted	I couldn't have been hefting you couldn't have been hefting he couldn't have been hefting we couldn't have been hefting you couldn't have been hefting they couldn't have been hefting

Interrogative form

Simple form	V-ing form
could I heft? could you heft? could he heft? could we heft? could you heft? could they heft?	could I be hefting? could you be hefting? could he be hefting? could we be hefting? could you be hefting? could they be hefting?
Perfect	V-ing perfect
could I have hefted? could you have hefted? could he have hefted? could we have hefted? could you have hefted? could they have hefted?	could I have been hefting? could you have been hefting? could he have been hefting? could we have been hefting? could you have been hefting? could they have been hefting?

Interro-negative form

Simple form	V-ing form
couldn't I heft? couldn't you heft? couldn't he heft? couldn't we heft? couldn't you heft? couldn't they heft?	couldn't I be hefting? couldn't you be hefting? couldn't he be hefting? couldn't we be hefting? couldn't you be hefting? couldn't they be hefting?
Perfect	V-ing perfect
couldn't I have hefted? couldn't you have hefted? couldn't he have hefted? couldn't we have hefted? couldn't you have hefted? couldn't they have hefted?	couldn't I have been hefting? couldn't you have been hefting? couldn't he have been hefting? couldn't we have been hefting? couldn't you have been hefting? couldn't they have been hefting?