English verb conjugation
COULD CARBURIZE

Regular verb: carburize - carburized - carburized

Affirmation

Simple form	V-ing form
I could carburize you could carburize he could carburize we could carburize you could carburize they could carburize	I could be carburizing you could be carburizing he could be carburizing we could be carburizing you could be carburizing they could be carburizing
Perfect	V-ing perfect
I could have carburized you could have carburized he could have carburized we could have carburized you could have carburized they could have carburized	I could have been carburizing you could have been carburizing he could have been carburizing we could have been carburizing you could have been carburizing they could have been carburizing

Negation

Simple form	V-ing form
I couldn't carburize you couldn't carburize he couldn't carburize we couldn't carburize you couldn't carburize they couldn't carburize	I couldn't be carburizing you couldn't be carburizing he couldn't be carburizing we couldn't be carburizing you couldn't be carburizing they couldn't be carburizing
Perfect	V-ing perfect
I couldn't have carburized you couldn't have carburized he couldn't have carburized we couldn't have carburized you couldn't have carburized they couldn't have carburized	I couldn't have been carburizing you couldn't have been carburizing he couldn't have been carburizing we couldn't have been carburizing you couldn't have been carburizing they couldn't have been carburizing

Interrogative form

Simple form	V-ing form
could I carburize? could you carburize? could he carburize? could we carburize? could you carburize? could they carburize?	could I be carburizing? could you be carburizing? could he be carburizing? could we be carburizing? could you be carburizing? could they be carburizing?
Perfect	V-ing perfect
could I have carburized? could you have carburized? could he have carburized? could we have carburized? could you have carburized? could they have carburized?	could I have been carburizing? could you have been carburizing? could he have been carburizing? could we have been carburizing? could you have been carburizing? could they have been carburizing?

Interro-negative form

Simple form	V-ing form
couldn't I carburize? couldn't you carburize? couldn't he carburize? couldn't we carburize? couldn't you carburize? couldn't they carburize?	couldn't I be carburizing? couldn't you be carburizing? couldn't he be carburizing? couldn't we be carburizing? couldn't you be carburizing? couldn't they be carburizing?
Perfect	V-ing perfect
couldn't I have carburized? couldn't you have carburized? couldn't he have carburized? couldn't we have carburized? couldn't you have carburized? couldn't they have carburized?	couldn't I have been carburizing? couldn't you have been carburizing? couldn't he have been carburizing? couldn't we have been carburizing? couldn't you have been carburizing? couldn't they have been carburizing?