English verb conjugation
COULD GRASS

Regular verb: grass - grassed - grassed

Affirmation

Simple form	V-ing form
I could grass you could grass he could grass we could grass you could grass they could grass	I could be grassing you could be grassing he could be grassing we could be grassing you could be grassing they could be grassing
Perfect	V-ing perfect
I could have grassed you could have grassed he could have grassed we could have grassed you could have grassed they could have grassed	I could have been grassing you could have been grassing he could have been grassing we could have been grassing you could have been grassing they could have been grassing

Negation

Simple form	V-ing form
I could not grass you could not grass he could not grass we could not grass you could not grass they could not grass	I could not be grassing you could not be grassing he could not be grassing we could not be grassing you could not be grassing they could not be grassing
Perfect	V-ing perfect
I could not have grassed you could not have grassed he could not have grassed we could not have grassed you could not have grassed they could not have grassed	I could not have been grassing you could not have been grassing he could not have been grassing we could not have been grassing you could not have been grassing they could not have been grassing

Interrogative form

Simple form	V-ing form
could I grass? could you grass? could he grass? could we grass? could you grass? could they grass?	could I be grassing? could you be grassing? could he be grassing? could we be grassing? could you be grassing? could they be grassing?
Perfect	V-ing perfect
could I have grassed? could you have grassed? could he have grassed? could we have grassed? could you have grassed? could they have grassed?	could I have been grassing? could you have been grassing? could he have been grassing? could we have been grassing? could you have been grassing? could they have been grassing?

Interro-negative form

Simple form	V-ing form
could I not grass? could you not grass? could he not grass? could we not grass? could you not grass? could they not grass?	could I not be grassing? could you not be grassing? could he not be grassing? could we not be grassing? could you not be grassing? could they not be grassing?
Perfect	V-ing perfect
could I not have grassed? could you not have grassed? could he not have grassed? could we not have grassed? could you not have grassed? could they not have grassed?	could I not have been grassing? could you not have been grassing? could he not have been grassing? could we not have been grassing? could you not have been grassing? could they not have been grassing?