English verb conjugation
COULD BILLET

Regular verb: billet - billeted - billeted

Affirmation

Simple form	V-ing form
I could billet you could billet she could billet we could billet you could billet they could billet	I could be billeting you could be billeting she could be billeting we could be billeting you could be billeting they could be billeting
Perfect	V-ing perfect
I could have billeted you could have billeted she could have billeted we could have billeted you could have billeted they could have billeted	I could have been billeting you could have been billeting she could have been billeting we could have been billeting you could have been billeting they could have been billeting

Negation

Simple form	V-ing form
I couldn't billet you couldn't billet she couldn't billet we couldn't billet you couldn't billet they couldn't billet	I couldn't be billeting you couldn't be billeting she couldn't be billeting we couldn't be billeting you couldn't be billeting they couldn't be billeting
Perfect	V-ing perfect
I couldn't have billeted you couldn't have billeted she couldn't have billeted we couldn't have billeted you couldn't have billeted they couldn't have billeted	I couldn't have been billeting you couldn't have been billeting she couldn't have been billeting we couldn't have been billeting you couldn't have been billeting they couldn't have been billeting

Interrogative form

Simple form	V-ing form
could I billet? could you billet? could she billet? could we billet? could you billet? could they billet?	could I be billeting? could you be billeting? could she be billeting? could we be billeting? could you be billeting? could they be billeting?
Perfect	V-ing perfect
could I have billeted? could you have billeted? could she have billeted? could we have billeted? could you have billeted? could they have billeted?	could I have been billeting? could you have been billeting? could she have been billeting? could we have been billeting? could you have been billeting? could they have been billeting?

Interro-negative form

Simple form	V-ing form
couldn't I billet? couldn't you billet? couldn't she billet? couldn't we billet? couldn't you billet? couldn't they billet?	couldn't I be billeting? couldn't you be billeting? couldn't she be billeting? couldn't we be billeting? couldn't you be billeting? couldn't they be billeting?
Perfect	V-ing perfect
couldn't I have billeted? couldn't you have billeted? couldn't she have billeted? couldn't we have billeted? couldn't you have billeted? couldn't they have billeted?	couldn't I have been billeting? couldn't you have been billeting? couldn't she have been billeting? couldn't we have been billeting? couldn't you have been billeting? couldn't they have been billeting?