English verb conjugation
COULD DISPLAY

Regular verb: display - displayed - displayed

Affirmation

Simple form	V-ing form
I could display you could display he could display we could display you could display they could display	I could be displaying you could be displaying he could be displaying we could be displaying you could be displaying they could be displaying
Perfect	V-ing perfect
I could have displayed you could have displayed he could have displayed we could have displayed you could have displayed they could have displayed	I could have been displaying you could have been displaying he could have been displaying we could have been displaying you could have been displaying they could have been displaying

Negation

Simple form	V-ing form
I couldn't display you couldn't display he couldn't display we couldn't display you couldn't display they couldn't display	I couldn't be displaying you couldn't be displaying he couldn't be displaying we couldn't be displaying you couldn't be displaying they couldn't be displaying
Perfect	V-ing perfect
I couldn't have displayed you couldn't have displayed he couldn't have displayed we couldn't have displayed you couldn't have displayed they couldn't have displayed	I couldn't have been displaying you couldn't have been displaying he couldn't have been displaying we couldn't have been displaying you couldn't have been displaying they couldn't have been displaying

Interrogative form

Simple form	V-ing form
could I display? could you display? could he display? could we display? could you display? could they display?	could I be displaying? could you be displaying? could he be displaying? could we be displaying? could you be displaying? could they be displaying?
Perfect	V-ing perfect
could I have displayed? could you have displayed? could he have displayed? could we have displayed? could you have displayed? could they have displayed?	could I have been displaying? could you have been displaying? could he have been displaying? could we have been displaying? could you have been displaying? could they have been displaying?

Interro-negative form

Simple form	V-ing form
couldn't I display? couldn't you display? couldn't he display? couldn't we display? couldn't you display? couldn't they display?	couldn't I be displaying? couldn't you be displaying? couldn't he be displaying? couldn't we be displaying? couldn't you be displaying? couldn't they be displaying?
Perfect	V-ing perfect
couldn't I have displayed? couldn't you have displayed? couldn't he have displayed? couldn't we have displayed? couldn't you have displayed? couldn't they have displayed?	couldn't I have been displaying? couldn't you have been displaying? couldn't he have been displaying? couldn't we have been displaying? couldn't you have been displaying? couldn't they have been displaying?