English verb conjugation
COULD CONCRETIZE

Regular verb: concretize - concretized - concretized

Affirmation

Simple form	V-ing form
I could concretize you could concretize he could concretize we could concretize you could concretize they could concretize	I could be concretizing you could be concretizing he could be concretizing we could be concretizing you could be concretizing they could be concretizing
Perfect	V-ing perfect
I could have concretized you could have concretized he could have concretized we could have concretized you could have concretized they could have concretized	I could have been concretizing you could have been concretizing he could have been concretizing we could have been concretizing you could have been concretizing they could have been concretizing

Negation

Simple form	V-ing form
I couldn't concretize you couldn't concretize he couldn't concretize we couldn't concretize you couldn't concretize they couldn't concretize	I couldn't be concretizing you couldn't be concretizing he couldn't be concretizing we couldn't be concretizing you couldn't be concretizing they couldn't be concretizing
Perfect	V-ing perfect
I couldn't have concretized you couldn't have concretized he couldn't have concretized we couldn't have concretized you couldn't have concretized they couldn't have concretized	I couldn't have been concretizing you couldn't have been concretizing he couldn't have been concretizing we couldn't have been concretizing you couldn't have been concretizing they couldn't have been concretizing

Interrogative form

Simple form	V-ing form
could I concretize? could you concretize? could he concretize? could we concretize? could you concretize? could they concretize?	could I be concretizing? could you be concretizing? could he be concretizing? could we be concretizing? could you be concretizing? could they be concretizing?
Perfect	V-ing perfect
could I have concretized? could you have concretized? could he have concretized? could we have concretized? could you have concretized? could they have concretized?	could I have been concretizing? could you have been concretizing? could he have been concretizing? could we have been concretizing? could you have been concretizing? could they have been concretizing?

Interro-negative form

Simple form	V-ing form
couldn't I concretize? couldn't you concretize? couldn't he concretize? couldn't we concretize? couldn't you concretize? couldn't they concretize?	couldn't I be concretizing? couldn't you be concretizing? couldn't he be concretizing? couldn't we be concretizing? couldn't you be concretizing? couldn't they be concretizing?
Perfect	V-ing perfect
couldn't I have concretized? couldn't you have concretized? couldn't he have concretized? couldn't we have concretized? couldn't you have concretized? couldn't they have concretized?	couldn't I have been concretizing? couldn't you have been concretizing? couldn't he have been concretizing? couldn't we have been concretizing? couldn't you have been concretizing? couldn't they have been concretizing?