English verb conjugation
COULD UPGRADE

Regular verb: upgrade - upgraded - upgraded

Affirmation

Simple form	V-ing form
I could upgrade you could upgrade she could upgrade we could upgrade you could upgrade they could upgrade	I could be upgrading you could be upgrading she 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 she 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 she 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 couldn't upgrade you couldn't upgrade she couldn't upgrade we couldn't upgrade you couldn't upgrade they couldn't upgrade	I couldn't be upgrading you couldn't be upgrading she couldn't be upgrading we couldn't be upgrading you couldn't be upgrading they couldn't be upgrading
Perfect	V-ing perfect
I couldn't have upgraded you couldn't have upgraded she couldn't have upgraded we couldn't have upgraded you couldn't have upgraded they couldn't have upgraded	I couldn't have been upgrading you couldn't have been upgrading she couldn't have been upgrading we couldn't have been upgrading you couldn't have been upgrading they couldn't have been upgrading

Interrogative form

Simple form	V-ing form
could I upgrade? could you upgrade? could she upgrade? could we upgrade? could you upgrade? could they upgrade?	could I be upgrading? could you be upgrading? could she 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 she 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 she 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
couldn't I upgrade? couldn't you upgrade? couldn't she upgrade? couldn't we upgrade? couldn't you upgrade? couldn't they upgrade?	couldn't I be upgrading? couldn't you be upgrading? couldn't she be upgrading? couldn't we be upgrading? couldn't you be upgrading? couldn't they be upgrading?
Perfect	V-ing perfect
couldn't I have upgraded? couldn't you have upgraded? couldn't she have upgraded? couldn't we have upgraded? couldn't you have upgraded? couldn't they have upgraded?	couldn't I have been upgrading? couldn't you have been upgrading? couldn't she have been upgrading? couldn't we have been upgrading? couldn't you have been upgrading? couldn't they have been upgrading?