English verb conjugation
COULD FRET

Regular verb: fret - fretted - fretted

Affirmation

Simple form	V-ing form
I could fret you could fret she could fret we could fret you could fret they could fret	I could be fretting you could be fretting she could be fretting we could be fretting you could be fretting they could be fretting
Perfect	V-ing perfect
I could have fretted you could have fretted she could have fretted we could have fretted you could have fretted they could have fretted	I could have been fretting you could have been fretting she could have been fretting we could have been fretting you could have been fretting they could have been fretting

Negation

Simple form	V-ing form
I couldn't fret you couldn't fret she couldn't fret we couldn't fret you couldn't fret they couldn't fret	I couldn't be fretting you couldn't be fretting she couldn't be fretting we couldn't be fretting you couldn't be fretting they couldn't be fretting
Perfect	V-ing perfect
I couldn't have fretted you couldn't have fretted she couldn't have fretted we couldn't have fretted you couldn't have fretted they couldn't have fretted	I couldn't have been fretting you couldn't have been fretting she couldn't have been fretting we couldn't have been fretting you couldn't have been fretting they couldn't have been fretting

Interrogative form

Simple form	V-ing form
could I fret? could you fret? could she fret? could we fret? could you fret? could they fret?	could I be fretting? could you be fretting? could she be fretting? could we be fretting? could you be fretting? could they be fretting?
Perfect	V-ing perfect
could I have fretted? could you have fretted? could she have fretted? could we have fretted? could you have fretted? could they have fretted?	could I have been fretting? could you have been fretting? could she have been fretting? could we have been fretting? could you have been fretting? could they have been fretting?

Interro-negative form

Simple form	V-ing form
couldn't I fret? couldn't you fret? couldn't she fret? couldn't we fret? couldn't you fret? couldn't they fret?	couldn't I be fretting? couldn't you be fretting? couldn't she be fretting? couldn't we be fretting? couldn't you be fretting? couldn't they be fretting?
Perfect	V-ing perfect
couldn't I have fretted? couldn't you have fretted? couldn't she have fretted? couldn't we have fretted? couldn't you have fretted? couldn't they have fretted?	couldn't I have been fretting? couldn't you have been fretting? couldn't she have been fretting? couldn't we have been fretting? couldn't you have been fretting? couldn't they have been fretting?