English verb conjugation
COULD UPGRADE

Regular verb: upgrade - upgraded - upgraded

Affirmation

Simple form	V-ing form
I could upgrade you could upgrade he could upgrade we could upgrade you could upgrade they could upgrade	I could be upgrading you could be upgrading he could be upgrading we could be upgrading you could be upgrading they could be upgrading
Perfect	V-ing perfect
I could have upgraded you could have upgraded he could have upgraded we could have upgraded you could have upgraded they could have upgraded	I could have been upgrading you could have been upgrading he could have been upgrading we could have been upgrading you could have been upgrading they could have been upgrading

Negation

Simple form	V-ing form
I could not upgrade you could not upgrade he could not upgrade we could not upgrade you could not upgrade they could not upgrade	I could not be upgrading you could not be upgrading he could not be upgrading we could not be upgrading you could not be upgrading they could not be upgrading
Perfect	V-ing perfect
I could not have upgraded you could not have upgraded he could not have upgraded we could not have upgraded you could not have upgraded they could not have upgraded	I could not have been upgrading you could not have been upgrading he could not have been upgrading we could not have been upgrading you could not have been upgrading they could not have been upgrading

Interrogative form

Simple form	V-ing form
could I upgrade? could you upgrade? could he upgrade? could we upgrade? could you upgrade? could they upgrade?	could I be upgrading? could you be upgrading? could he be upgrading? could we be upgrading? could you be upgrading? could they be upgrading?
Perfect	V-ing perfect
could I have upgraded? could you have upgraded? could he have upgraded? could we have upgraded? could you have upgraded? could they have upgraded?	could I have been upgrading? could you have been upgrading? could he have been upgrading? could we have been upgrading? could you have been upgrading? could they have been upgrading?

Interro-negative form

Simple form	V-ing form
could I not upgrade? could you not upgrade? could he not upgrade? could we not upgrade? could you not upgrade? could they not upgrade?	could I not be upgrading? could you not be upgrading? could he not be upgrading? could we not be upgrading? could you not be upgrading? could they not be upgrading?
Perfect	V-ing perfect
could I not have upgraded? could you not have upgraded? could he not have upgraded? could we not have upgraded? could you not have upgraded? could they not have upgraded?	could I not have been upgrading? could you not have been upgrading? could he not have been upgrading? could we not have been upgrading? could you not have been upgrading? could they not have been upgrading?