English verb conjugation
COULD PREP

Regular verb: prep - preped - preped

Affirmation

Simple form	V-ing form
I could prep you could prep he could prep we could prep you could prep they could prep	I could be preping you could be preping he could be preping we could be preping you could be preping they could be preping
Perfect	V-ing perfect
I could have preped you could have preped he could have preped we could have preped you could have preped they could have preped	I could have been preping you could have been preping he could have been preping we could have been preping you could have been preping they could have been preping

Negation

Simple form	V-ing form
I couldn't prep you couldn't prep he couldn't prep we couldn't prep you couldn't prep they couldn't prep	I couldn't be preping you couldn't be preping he couldn't be preping we couldn't be preping you couldn't be preping they couldn't be preping
Perfect	V-ing perfect
I couldn't have preped you couldn't have preped he couldn't have preped we couldn't have preped you couldn't have preped they couldn't have preped	I couldn't have been preping you couldn't have been preping he couldn't have been preping we couldn't have been preping you couldn't have been preping they couldn't have been preping

Interrogative form

Simple form	V-ing form
could I prep? could you prep? could he prep? could we prep? could you prep? could they prep?	could I be preping? could you be preping? could he be preping? could we be preping? could you be preping? could they be preping?
Perfect	V-ing perfect
could I have preped? could you have preped? could he have preped? could we have preped? could you have preped? could they have preped?	could I have been preping? could you have been preping? could he have been preping? could we have been preping? could you have been preping? could they have been preping?

Interro-negative form

Simple form	V-ing form
couldn't I prep? couldn't you prep? couldn't he prep? couldn't we prep? couldn't you prep? couldn't they prep?	couldn't I be preping? couldn't you be preping? couldn't he be preping? couldn't we be preping? couldn't you be preping? couldn't they be preping?
Perfect	V-ing perfect
couldn't I have preped? couldn't you have preped? couldn't he have preped? couldn't we have preped? couldn't you have preped? couldn't they have preped?	couldn't I have been preping? couldn't you have been preping? couldn't he have been preping? couldn't we have been preping? couldn't you have been preping? couldn't they have been preping?