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 could not prep you could not prep he could not prep we could not prep you could not prep they could not prep	I could not be preping you could not be preping he could not be preping we could not be preping you could not be preping they could not be preping
Perfect	V-ing perfect
I could not have preped you could not have preped he could not have preped we could not have preped you could not have preped they could not have preped	I could not have been preping you could not have been preping he could not have been preping we could not have been preping you could not have been preping they could not 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
could I not prep? could you not prep? could he not prep? could we not prep? could you not prep? could they not prep?	could I not be preping? could you not be preping? could he not be preping? could we not be preping? could you not be preping? could they not be preping?
Perfect	V-ing perfect
could I not have preped? could you not have preped? could he not have preped? could we not have preped? could you not have preped? could they not have preped?	could I not have been preping? could you not have been preping? could he not have been preping? could we not have been preping? could you not have been preping? could they not have been preping?