English verb conjugation
COULD CONCAVE

Regular verb: concave - concaved - concaved

Affirmation

Simple form	V-ing form
I could concave you could concave she could concave we could concave you could concave they could concave	I could be concaving you could be concaving she could be concaving we could be concaving you could be concaving they could be concaving
Perfect	V-ing perfect
I could have concaved you could have concaved she could have concaved we could have concaved you could have concaved they could have concaved	I could have been concaving you could have been concaving she could have been concaving we could have been concaving you could have been concaving they could have been concaving

Negation

Simple form	V-ing form
I couldn't concave you couldn't concave she couldn't concave we couldn't concave you couldn't concave they couldn't concave	I couldn't be concaving you couldn't be concaving she couldn't be concaving we couldn't be concaving you couldn't be concaving they couldn't be concaving
Perfect	V-ing perfect
I couldn't have concaved you couldn't have concaved she couldn't have concaved we couldn't have concaved you couldn't have concaved they couldn't have concaved	I couldn't have been concaving you couldn't have been concaving she couldn't have been concaving we couldn't have been concaving you couldn't have been concaving they couldn't have been concaving

Interrogative form

Simple form	V-ing form
could I concave? could you concave? could she concave? could we concave? could you concave? could they concave?	could I be concaving? could you be concaving? could she be concaving? could we be concaving? could you be concaving? could they be concaving?
Perfect	V-ing perfect
could I have concaved? could you have concaved? could she have concaved? could we have concaved? could you have concaved? could they have concaved?	could I have been concaving? could you have been concaving? could she have been concaving? could we have been concaving? could you have been concaving? could they have been concaving?

Interro-negative form

Simple form	V-ing form
couldn't I concave? couldn't you concave? couldn't she concave? couldn't we concave? couldn't you concave? couldn't they concave?	couldn't I be concaving? couldn't you be concaving? couldn't she be concaving? couldn't we be concaving? couldn't you be concaving? couldn't they be concaving?
Perfect	V-ing perfect
couldn't I have concaved? couldn't you have concaved? couldn't she have concaved? couldn't we have concaved? couldn't you have concaved? couldn't they have concaved?	couldn't I have been concaving? couldn't you have been concaving? couldn't she have been concaving? couldn't we have been concaving? couldn't you have been concaving? couldn't they have been concaving?