I could crystallize you could crystallize she could crystallize we could crystallize you could crystallize they could crystallize
V-ing form
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
I could have crystallized you could have crystallized she could have crystallized we could have crystallized you could have crystallized they could have crystallized
V-ing perfect
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
I could not crystallize you could not crystallize she could not crystallize we could not crystallize you could not crystallize they could not crystallize
V-ing form
I could not be crystallizing you could not be crystallizing she could not be crystallizing we could not be crystallizing you could not be crystallizing they could not be crystallizing
Perfect
I could not have crystallized you could not have crystallized she could not have crystallized we could not have crystallized you could not have crystallized they could not have crystallized
V-ing perfect
I could not have been crystallizing you could not have been crystallizing she could not have been crystallizing we could not have been crystallizing you could not have been crystallizing they could not have been crystallizing
Interrogative form
Simple form
could I crystallize? could you crystallize? could she crystallize? could we crystallize? could you crystallize? could they crystallize?
V-ing form
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
could I have crystallized? could you have crystallized? could she have crystallized? could we have crystallized? could you have crystallized? could they have crystallized?
V-ing perfect
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
could I not crystallize? could you not crystallize? could she not crystallize? could we not crystallize? could you not crystallize? could they not crystallize?
V-ing form
could I not be crystallizing? could you not be crystallizing? could she not be crystallizing? could we not be crystallizing? could you not be crystallizing? could they not be crystallizing?
Perfect
could I not have crystallized? could you not have crystallized? could she not have crystallized? could we not have crystallized? could you not have crystallized? could they not have crystallized?
V-ing perfect
could I not have been crystallizing? could you not have been crystallizing? could she not have been crystallizing? could we not have been crystallizing? could you not have been crystallizing? could they not have been crystallizing?