English verb conjugation
COULD DO

Irregular verb: do - did - done

Affirmation

Simple form	V-ing form
I could do you could do she could do we could do you could do they could do	I could be doing you could be doing she could be doing we could be doing you could be doing they could be doing
Perfect	V-ing perfect
I could have done you could have done she could have done we could have done you could have done they could have done	I could have been doing you could have been doing she could have been doing we could have been doing you could have been doing they could have been doing

Negation

Simple form	V-ing form
I could not do you could not do she could not do we could not do you could not do they could not do	I could not be doing you could not be doing she could not be doing we could not be doing you could not be doing they could not be doing
Perfect	V-ing perfect
I could not have done you could not have done she could not have done we could not have done you could not have done they could not have done	I could not have been doing you could not have been doing she could not have been doing we could not have been doing you could not have been doing they could not have been doing

Interrogative form

Simple form	V-ing form
could I do? could you do? could she do? could we do? could you do? could they do?	could I be doing? could you be doing? could she be doing? could we be doing? could you be doing? could they be doing?
Perfect	V-ing perfect
could I have done? could you have done? could she have done? could we have done? could you have done? could they have done?	could I have been doing? could you have been doing? could she have been doing? could we have been doing? could you have been doing? could they have been doing?

Interro-negative form

Simple form	V-ing form
could I not do? could you not do? could she not do? could we not do? could you not do? could they not do?	could I not be doing? could you not be doing? could she not be doing? could we not be doing? could you not be doing? could they not be doing?
Perfect	V-ing perfect
could I not have done? could you not have done? could she not have done? could we not have done? could you not have done? could they not have done?	could I not have been doing? could you not have been doing? could she not have been doing? could we not have been doing? could you not have been doing? could they not have been doing?