English verb conjugation
COULD CRYSTALLIZE

Regular verb: crystallize - crystallized - crystallized

Affirmation

Simple form	V-ing form
I could crystallize you could crystallize she could crystallize we could crystallize you could crystallize they could crystallize	I could be crystallizing you could be crystallizing she could be crystallizing we could be crystallizing you could be crystallizing they could be crystallizing
Perfect	V-ing perfect
I could have crystallized you could have crystallized she could have crystallized we could have crystallized you could have crystallized they could have crystallized	I could have been crystallizing you could have been crystallizing she could have been crystallizing we could have been crystallizing you could have been crystallizing they could have been crystallizing

Negation

Simple form	V-ing form
I couldn't crystallize you couldn't crystallize she couldn't crystallize we couldn't crystallize you couldn't crystallize they couldn't crystallize	I couldn't be crystallizing you couldn't be crystallizing she couldn't be crystallizing we couldn't be crystallizing you couldn't be crystallizing they couldn't be crystallizing
Perfect	V-ing perfect
I couldn't have crystallized you couldn't have crystallized she couldn't have crystallized we couldn't have crystallized you couldn't have crystallized they couldn't have crystallized	I couldn't have been crystallizing you couldn't have been crystallizing she couldn't have been crystallizing we couldn't have been crystallizing you couldn't have been crystallizing they couldn't have been crystallizing

Interrogative form

Simple form	V-ing form
could I crystallize? could you crystallize? could she crystallize? could we crystallize? could you crystallize? could they crystallize?	could I be crystallizing? could you be crystallizing? could she be crystallizing? could we be crystallizing? could you be crystallizing? could they be crystallizing?
Perfect	V-ing perfect
could I have crystallized? could you have crystallized? could she have crystallized? could we have crystallized? could you have crystallized? could they have crystallized?	could I have been crystallizing? could you have been crystallizing? could she have been crystallizing? could we have been crystallizing? could you have been crystallizing? could they have been crystallizing?

Interro-negative form

Simple form	V-ing form
couldn't I crystallize? couldn't you crystallize? couldn't she crystallize? couldn't we crystallize? couldn't you crystallize? couldn't they crystallize?	couldn't I be crystallizing? couldn't you be crystallizing? couldn't she be crystallizing? couldn't we be crystallizing? couldn't you be crystallizing? couldn't they be crystallizing?
Perfect	V-ing perfect
couldn't I have crystallized? couldn't you have crystallized? couldn't she have crystallized? couldn't we have crystallized? couldn't you have crystallized? couldn't they have crystallized?	couldn't I have been crystallizing? couldn't you have been crystallizing? couldn't she have been crystallizing? couldn't we have been crystallizing? couldn't you have been crystallizing? couldn't they have been crystallizing?