English verb conjugation
COULD VITRIFY

Regular verb: vitrify - vitrified - vitrified

Affirmation

Simple form	V-ing form
I could vitrify you could vitrify he could vitrify we could vitrify you could vitrify they could vitrify	I could be vitrifying you could be vitrifying he could be vitrifying we could be vitrifying you could be vitrifying they could be vitrifying
Perfect	V-ing perfect
I could have vitrified you could have vitrified he could have vitrified we could have vitrified you could have vitrified they could have vitrified	I could have been vitrifying you could have been vitrifying he could have been vitrifying we could have been vitrifying you could have been vitrifying they could have been vitrifying

Negation

Simple form	V-ing form
I could not vitrify you could not vitrify he could not vitrify we could not vitrify you could not vitrify they could not vitrify	I could not be vitrifying you could not be vitrifying he could not be vitrifying we could not be vitrifying you could not be vitrifying they could not be vitrifying
Perfect	V-ing perfect
I could not have vitrified you could not have vitrified he could not have vitrified we could not have vitrified you could not have vitrified they could not have vitrified	I could not have been vitrifying you could not have been vitrifying he could not have been vitrifying we could not have been vitrifying you could not have been vitrifying they could not have been vitrifying

Interrogative form

Simple form	V-ing form
could I vitrify? could you vitrify? could he vitrify? could we vitrify? could you vitrify? could they vitrify?	could I be vitrifying? could you be vitrifying? could he be vitrifying? could we be vitrifying? could you be vitrifying? could they be vitrifying?
Perfect	V-ing perfect
could I have vitrified? could you have vitrified? could he have vitrified? could we have vitrified? could you have vitrified? could they have vitrified?	could I have been vitrifying? could you have been vitrifying? could he have been vitrifying? could we have been vitrifying? could you have been vitrifying? could they have been vitrifying?

Interro-negative form

Simple form	V-ing form
could I not vitrify? could you not vitrify? could he not vitrify? could we not vitrify? could you not vitrify? could they not vitrify?	could I not be vitrifying? could you not be vitrifying? could he not be vitrifying? could we not be vitrifying? could you not be vitrifying? could they not be vitrifying?
Perfect	V-ing perfect
could I not have vitrified? could you not have vitrified? could he not have vitrified? could we not have vitrified? could you not have vitrified? could they not have vitrified?	could I not have been vitrifying? could you not have been vitrifying? could he not have been vitrifying? could we not have been vitrifying? could you not have been vitrifying? could they not have been vitrifying?