English verb conjugation
COULD CONCOCT

Regular verb: concoct - concocted - concocted

Affirmation

Simple form	V-ing form
I could concoct you could concoct he could concoct we could concoct you could concoct they could concoct	I could be concocting you could be concocting he could be concocting we could be concocting you could be concocting they could be concocting
Perfect	V-ing perfect
I could have concocted you could have concocted he could have concocted we could have concocted you could have concocted they could have concocted	I could have been concocting you could have been concocting he could have been concocting we could have been concocting you could have been concocting they could have been concocting

Negation

Simple form	V-ing form
I couldn't concoct you couldn't concoct he couldn't concoct we couldn't concoct you couldn't concoct they couldn't concoct	I couldn't be concocting you couldn't be concocting he couldn't be concocting we couldn't be concocting you couldn't be concocting they couldn't be concocting
Perfect	V-ing perfect
I couldn't have concocted you couldn't have concocted he couldn't have concocted we couldn't have concocted you couldn't have concocted they couldn't have concocted	I couldn't have been concocting you couldn't have been concocting he couldn't have been concocting we couldn't have been concocting you couldn't have been concocting they couldn't have been concocting

Interrogative form

Simple form	V-ing form
could I concoct? could you concoct? could he concoct? could we concoct? could you concoct? could they concoct?	could I be concocting? could you be concocting? could he be concocting? could we be concocting? could you be concocting? could they be concocting?
Perfect	V-ing perfect
could I have concocted? could you have concocted? could he have concocted? could we have concocted? could you have concocted? could they have concocted?	could I have been concocting? could you have been concocting? could he have been concocting? could we have been concocting? could you have been concocting? could they have been concocting?

Interro-negative form

Simple form	V-ing form
couldn't I concoct? couldn't you concoct? couldn't he concoct? couldn't we concoct? couldn't you concoct? couldn't they concoct?	couldn't I be concocting? couldn't you be concocting? couldn't he be concocting? couldn't we be concocting? couldn't you be concocting? couldn't they be concocting?
Perfect	V-ing perfect
couldn't I have concocted? couldn't you have concocted? couldn't he have concocted? couldn't we have concocted? couldn't you have concocted? couldn't they have concocted?	couldn't I have been concocting? couldn't you have been concocting? couldn't he have been concocting? couldn't we have been concocting? couldn't you have been concocting? couldn't they have been concocting?