English verb conjugation
COULD BUZZ

Regular verb: buzz - buzzed - buzzed

Affirmation

Simple form	V-ing form
I could buzz you could buzz he could buzz we could buzz you could buzz they could buzz	I could be buzzing you could be buzzing he could be buzzing we could be buzzing you could be buzzing they could be buzzing
Perfect	V-ing perfect
I could have buzzed you could have buzzed he could have buzzed we could have buzzed you could have buzzed they could have buzzed	I could have been buzzing you could have been buzzing he could have been buzzing we could have been buzzing you could have been buzzing they could have been buzzing

Negation

Simple form	V-ing form
I could not buzz you could not buzz he could not buzz we could not buzz you could not buzz they could not buzz	I could not be buzzing you could not be buzzing he could not be buzzing we could not be buzzing you could not be buzzing they could not be buzzing
Perfect	V-ing perfect
I could not have buzzed you could not have buzzed he could not have buzzed we could not have buzzed you could not have buzzed they could not have buzzed	I could not have been buzzing you could not have been buzzing he could not have been buzzing we could not have been buzzing you could not have been buzzing they could not have been buzzing

Interrogative form

Simple form	V-ing form
could I buzz? could you buzz? could he buzz? could we buzz? could you buzz? could they buzz?	could I be buzzing? could you be buzzing? could he be buzzing? could we be buzzing? could you be buzzing? could they be buzzing?
Perfect	V-ing perfect
could I have buzzed? could you have buzzed? could he have buzzed? could we have buzzed? could you have buzzed? could they have buzzed?	could I have been buzzing? could you have been buzzing? could he have been buzzing? could we have been buzzing? could you have been buzzing? could they have been buzzing?

Interro-negative form

Simple form	V-ing form
could I not buzz? could you not buzz? could he not buzz? could we not buzz? could you not buzz? could they not buzz?	could I not be buzzing? could you not be buzzing? could he not be buzzing? could we not be buzzing? could you not be buzzing? could they not be buzzing?
Perfect	V-ing perfect
could I not have buzzed? could you not have buzzed? could he not have buzzed? could we not have buzzed? could you not have buzzed? could they not have buzzed?	could I not have been buzzing? could you not have been buzzing? could he not have been buzzing? could we not have been buzzing? could you not have been buzzing? could they not have been buzzing?