English verb conjugation
COULD MARK MARK

Regular verb: mark mark - mark marked - mark marked

Warning, this verb may not exist. Conjugation is given as example.

Affirmation

Simple form	V-ing form
I could mark mark you could mark mark he could mark mark we could mark mark you could mark mark they could mark mark	I could be mark marking you could be mark marking he could be mark marking we could be mark marking you could be mark marking they could be mark marking
Perfect	V-ing perfect
I could have mark marked you could have mark marked he could have mark marked we could have mark marked you could have mark marked they could have mark marked	I could have been mark marking you could have been mark marking he could have been mark marking we could have been mark marking you could have been mark marking they could have been mark marking

Negation

Simple form	V-ing form
I could not mark mark you could not mark mark he could not mark mark we could not mark mark you could not mark mark they could not mark mark	I could not be mark marking you could not be mark marking he could not be mark marking we could not be mark marking you could not be mark marking they could not be mark marking
Perfect	V-ing perfect
I could not have mark marked you could not have mark marked he could not have mark marked we could not have mark marked you could not have mark marked they could not have mark marked	I could not have been mark marking you could not have been mark marking he could not have been mark marking we could not have been mark marking you could not have been mark marking they could not have been mark marking

Interrogative form

Simple form	V-ing form
could I mark mark? could you mark mark? could he mark mark? could we mark mark? could you mark mark? could they mark mark?	could I be mark marking? could you be mark marking? could he be mark marking? could we be mark marking? could you be mark marking? could they be mark marking?
Perfect	V-ing perfect
could I have mark marked? could you have mark marked? could he have mark marked? could we have mark marked? could you have mark marked? could they have mark marked?	could I have been mark marking? could you have been mark marking? could he have been mark marking? could we have been mark marking? could you have been mark marking? could they have been mark marking?

Interro-negative form

Simple form	V-ing form
could I not mark mark? could you not mark mark? could he not mark mark? could we not mark mark? could you not mark mark? could they not mark mark?	could I not be mark marking? could you not be mark marking? could he not be mark marking? could we not be mark marking? could you not be mark marking? could they not be mark marking?
Perfect	V-ing perfect
could I not have mark marked? could you not have mark marked? could he not have mark marked? could we not have mark marked? could you not have mark marked? could they not have mark marked?	could I not have been mark marking? could you not have been mark marking? could he not have been mark marking? could we not have been mark marking? could you not have been mark marking? could they not have been mark marking?