English verb conjugation
COULD PREEN

Regular verb: preen - preened - preened

Affirmation

Simple form	V-ing form
I could preen you could preen she could preen we could preen you could preen they could preen	I could be preening you could be preening she could be preening we could be preening you could be preening they could be preening
Perfect	V-ing perfect
I could have preened you could have preened she could have preened we could have preened you could have preened they could have preened	I could have been preening you could have been preening she could have been preening we could have been preening you could have been preening they could have been preening

Negation

Simple form	V-ing form
I couldn't preen you couldn't preen she couldn't preen we couldn't preen you couldn't preen they couldn't preen	I couldn't be preening you couldn't be preening she couldn't be preening we couldn't be preening you couldn't be preening they couldn't be preening
Perfect	V-ing perfect
I couldn't have preened you couldn't have preened she couldn't have preened we couldn't have preened you couldn't have preened they couldn't have preened	I couldn't have been preening you couldn't have been preening she couldn't have been preening we couldn't have been preening you couldn't have been preening they couldn't have been preening

Interrogative form

Simple form	V-ing form
could I preen? could you preen? could she preen? could we preen? could you preen? could they preen?	could I be preening? could you be preening? could she be preening? could we be preening? could you be preening? could they be preening?
Perfect	V-ing perfect
could I have preened? could you have preened? could she have preened? could we have preened? could you have preened? could they have preened?	could I have been preening? could you have been preening? could she have been preening? could we have been preening? could you have been preening? could they have been preening?

Interro-negative form

Simple form	V-ing form
couldn't I preen? couldn't you preen? couldn't she preen? couldn't we preen? couldn't you preen? couldn't they preen?	couldn't I be preening? couldn't you be preening? couldn't she be preening? couldn't we be preening? couldn't you be preening? couldn't they be preening?
Perfect	V-ing perfect
couldn't I have preened? couldn't you have preened? couldn't she have preened? couldn't we have preened? couldn't you have preened? couldn't they have preened?	couldn't I have been preening? couldn't you have been preening? couldn't she have been preening? couldn't we have been preening? couldn't you have been preening? couldn't they have been preening?