English verb conjugation
COULD UNBUTTON

Regular verb: unbutton - unbuttoned - unbuttoned

Affirmation

Simple form	V-ing form
I could unbutton you could unbutton she could unbutton we could unbutton you could unbutton they could unbutton	I could be unbuttoning you could be unbuttoning she could be unbuttoning we could be unbuttoning you could be unbuttoning they could be unbuttoning
Perfect	V-ing perfect
I could have unbuttoned you could have unbuttoned she could have unbuttoned we could have unbuttoned you could have unbuttoned they could have unbuttoned	I could have been unbuttoning you could have been unbuttoning she could have been unbuttoning we could have been unbuttoning you could have been unbuttoning they could have been unbuttoning

Negation

Simple form	V-ing form
I couldn't unbutton you couldn't unbutton she couldn't unbutton we couldn't unbutton you couldn't unbutton they couldn't unbutton	I couldn't be unbuttoning you couldn't be unbuttoning she couldn't be unbuttoning we couldn't be unbuttoning you couldn't be unbuttoning they couldn't be unbuttoning
Perfect	V-ing perfect
I couldn't have unbuttoned you couldn't have unbuttoned she couldn't have unbuttoned we couldn't have unbuttoned you couldn't have unbuttoned they couldn't have unbuttoned	I couldn't have been unbuttoning you couldn't have been unbuttoning she couldn't have been unbuttoning we couldn't have been unbuttoning you couldn't have been unbuttoning they couldn't have been unbuttoning

Interrogative form

Simple form	V-ing form
could I unbutton? could you unbutton? could she unbutton? could we unbutton? could you unbutton? could they unbutton?	could I be unbuttoning? could you be unbuttoning? could she be unbuttoning? could we be unbuttoning? could you be unbuttoning? could they be unbuttoning?
Perfect	V-ing perfect
could I have unbuttoned? could you have unbuttoned? could she have unbuttoned? could we have unbuttoned? could you have unbuttoned? could they have unbuttoned?	could I have been unbuttoning? could you have been unbuttoning? could she have been unbuttoning? could we have been unbuttoning? could you have been unbuttoning? could they have been unbuttoning?

Interro-negative form

Simple form	V-ing form
couldn't I unbutton? couldn't you unbutton? couldn't she unbutton? couldn't we unbutton? couldn't you unbutton? couldn't they unbutton?	couldn't I be unbuttoning? couldn't you be unbuttoning? couldn't she be unbuttoning? couldn't we be unbuttoning? couldn't you be unbuttoning? couldn't they be unbuttoning?
Perfect	V-ing perfect
couldn't I have unbuttoned? couldn't you have unbuttoned? couldn't she have unbuttoned? couldn't we have unbuttoned? couldn't you have unbuttoned? couldn't they have unbuttoned?	couldn't I have been unbuttoning? couldn't you have been unbuttoning? couldn't she have been unbuttoning? couldn't we have been unbuttoning? couldn't you have been unbuttoning? couldn't they have been unbuttoning?