English verb conjugation
COULD ACE

Regular verb: ace - aced - aced

Affirmation

Simple form	V-ing form
I could ace you could ace he could ace we could ace you could ace they could ace	I could be acing you could be acing he could be acing we could be acing you could be acing they could be acing
Perfect	V-ing perfect
I could have aced you could have aced he could have aced we could have aced you could have aced they could have aced	I could have been acing you could have been acing he could have been acing we could have been acing you could have been acing they could have been acing

Negation

Simple form	V-ing form
I couldn't ace you couldn't ace he couldn't ace we couldn't ace you couldn't ace they couldn't ace	I couldn't be acing you couldn't be acing he couldn't be acing we couldn't be acing you couldn't be acing they couldn't be acing
Perfect	V-ing perfect
I couldn't have aced you couldn't have aced he couldn't have aced we couldn't have aced you couldn't have aced they couldn't have aced	I couldn't have been acing you couldn't have been acing he couldn't have been acing we couldn't have been acing you couldn't have been acing they couldn't have been acing

Interrogative form

Simple form	V-ing form
could I ace? could you ace? could he ace? could we ace? could you ace? could they ace?	could I be acing? could you be acing? could he be acing? could we be acing? could you be acing? could they be acing?
Perfect	V-ing perfect
could I have aced? could you have aced? could he have aced? could we have aced? could you have aced? could they have aced?	could I have been acing? could you have been acing? could he have been acing? could we have been acing? could you have been acing? could they have been acing?

Interro-negative form

Simple form	V-ing form
couldn't I ace? couldn't you ace? couldn't he ace? couldn't we ace? couldn't you ace? couldn't they ace?	couldn't I be acing? couldn't you be acing? couldn't he be acing? couldn't we be acing? couldn't you be acing? couldn't they be acing?
Perfect	V-ing perfect
couldn't I have aced? couldn't you have aced? couldn't he have aced? couldn't we have aced? couldn't you have aced? couldn't they have aced?	couldn't I have been acing? couldn't you have been acing? couldn't he have been acing? couldn't we have been acing? couldn't you have been acing? couldn't they have been acing?