English verb conjugation
COULD CONCAVE

Regular verb: concave - concaved - concaved

Affirmation

Simple form	V-ing form
I could concave you could concave he could concave we could concave you could concave they could concave	I could be concaving you could be concaving he 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 he 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 he 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 he 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 he 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 he 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 he 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 he concave? could we concave? could you concave? could they concave?	could I be concaving? could you be concaving? could he 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 he 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 he 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 he 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 he 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 he 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 he have been concaving? couldn't we have been concaving? couldn't you have been concaving? couldn't they have been concaving?