English verb conjugation
COULD UNBOX

Regular verb: unbox - unboxed - unboxed

Affirmation

Simple form	V-ing form
I could unbox you could unbox she could unbox we could unbox you could unbox they could unbox	I could be unboxing you could be unboxing she could be unboxing we could be unboxing you could be unboxing they could be unboxing
Perfect	V-ing perfect
I could have unboxed you could have unboxed she could have unboxed we could have unboxed you could have unboxed they could have unboxed	I could have been unboxing you could have been unboxing she could have been unboxing we could have been unboxing you could have been unboxing they could have been unboxing

Negation

Simple form	V-ing form
I couldn't unbox you couldn't unbox she couldn't unbox we couldn't unbox you couldn't unbox they couldn't unbox	I couldn't be unboxing you couldn't be unboxing she couldn't be unboxing we couldn't be unboxing you couldn't be unboxing they couldn't be unboxing
Perfect	V-ing perfect
I couldn't have unboxed you couldn't have unboxed she couldn't have unboxed we couldn't have unboxed you couldn't have unboxed they couldn't have unboxed	I couldn't have been unboxing you couldn't have been unboxing she couldn't have been unboxing we couldn't have been unboxing you couldn't have been unboxing they couldn't have been unboxing

Interrogative form

Simple form	V-ing form
could I unbox? could you unbox? could she unbox? could we unbox? could you unbox? could they unbox?	could I be unboxing? could you be unboxing? could she be unboxing? could we be unboxing? could you be unboxing? could they be unboxing?
Perfect	V-ing perfect
could I have unboxed? could you have unboxed? could she have unboxed? could we have unboxed? could you have unboxed? could they have unboxed?	could I have been unboxing? could you have been unboxing? could she have been unboxing? could we have been unboxing? could you have been unboxing? could they have been unboxing?

Interro-negative form

Simple form	V-ing form
couldn't I unbox? couldn't you unbox? couldn't she unbox? couldn't we unbox? couldn't you unbox? couldn't they unbox?	couldn't I be unboxing? couldn't you be unboxing? couldn't she be unboxing? couldn't we be unboxing? couldn't you be unboxing? couldn't they be unboxing?
Perfect	V-ing perfect
couldn't I have unboxed? couldn't you have unboxed? couldn't she have unboxed? couldn't we have unboxed? couldn't you have unboxed? couldn't they have unboxed?	couldn't I have been unboxing? couldn't you have been unboxing? couldn't she have been unboxing? couldn't we have been unboxing? couldn't you have been unboxing? couldn't they have been unboxing?