English verb conjugation
CAN UPGRADE

Regular verb: upgrade - upgraded - upgraded

Affirmation

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

Negation

Simple form	V-ing form
I can't upgrade you can't upgrade he can't upgrade we can't upgrade you can't upgrade they can't upgrade	I can't be upgrading you can't be upgrading he can't be upgrading we can't be upgrading you can't be upgrading they can't be upgrading
Perfect	V-ing perfect
I can't have upgraded you can't have upgraded he can't have upgraded we can't have upgraded you can't have upgraded they can't have upgraded	I can't have been upgrading you can't have been upgrading he can't have been upgrading we can't have been upgrading you can't have been upgrading they can't have been upgrading

Interrogative form

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

Interro-negative form

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