English verb conjugation
COULD LEAVEN

Regular verb: leaven - leavened - leavened

Affirmation

Simple form	V-ing form
I could leaven you could leaven he could leaven we could leaven you could leaven they could leaven	I could be leavening you could be leavening he could be leavening we could be leavening you could be leavening they could be leavening
Perfect	V-ing perfect
I could have leavened you could have leavened he could have leavened we could have leavened you could have leavened they could have leavened	I could have been leavening you could have been leavening he could have been leavening we could have been leavening you could have been leavening they could have been leavening

Negation

Simple form	V-ing form
I couldn't leaven you couldn't leaven he couldn't leaven we couldn't leaven you couldn't leaven they couldn't leaven	I couldn't be leavening you couldn't be leavening he couldn't be leavening we couldn't be leavening you couldn't be leavening they couldn't be leavening
Perfect	V-ing perfect
I couldn't have leavened you couldn't have leavened he couldn't have leavened we couldn't have leavened you couldn't have leavened they couldn't have leavened	I couldn't have been leavening you couldn't have been leavening he couldn't have been leavening we couldn't have been leavening you couldn't have been leavening they couldn't have been leavening

Interrogative form

Simple form	V-ing form
could I leaven? could you leaven? could he leaven? could we leaven? could you leaven? could they leaven?	could I be leavening? could you be leavening? could he be leavening? could we be leavening? could you be leavening? could they be leavening?
Perfect	V-ing perfect
could I have leavened? could you have leavened? could he have leavened? could we have leavened? could you have leavened? could they have leavened?	could I have been leavening? could you have been leavening? could he have been leavening? could we have been leavening? could you have been leavening? could they have been leavening?

Interro-negative form

Simple form	V-ing form
couldn't I leaven? couldn't you leaven? couldn't he leaven? couldn't we leaven? couldn't you leaven? couldn't they leaven?	couldn't I be leavening? couldn't you be leavening? couldn't he be leavening? couldn't we be leavening? couldn't you be leavening? couldn't they be leavening?
Perfect	V-ing perfect
couldn't I have leavened? couldn't you have leavened? couldn't he have leavened? couldn't we have leavened? couldn't you have leavened? couldn't they have leavened?	couldn't I have been leavening? couldn't you have been leavening? couldn't he have been leavening? couldn't we have been leavening? couldn't you have been leavening? couldn't they have been leavening?