English verb conjugation
COULD SOLVE

Regular verb: solve - solved - solved

Affirmation

Simple form	V-ing form
I could solve you could solve she could solve we could solve you could solve they could solve	I could be solving you could be solving she could be solving we could be solving you could be solving they could be solving
Perfect	V-ing perfect
I could have solved you could have solved she could have solved we could have solved you could have solved they could have solved	I could have been solving you could have been solving she could have been solving we could have been solving you could have been solving they could have been solving

Negation

Simple form	V-ing form
I could not solve you could not solve she could not solve we could not solve you could not solve they could not solve	I could not be solving you could not be solving she could not be solving we could not be solving you could not be solving they could not be solving
Perfect	V-ing perfect
I could not have solved you could not have solved she could not have solved we could not have solved you could not have solved they could not have solved	I could not have been solving you could not have been solving she could not have been solving we could not have been solving you could not have been solving they could not have been solving

Interrogative form

Simple form	V-ing form
could I solve? could you solve? could she solve? could we solve? could you solve? could they solve?	could I be solving? could you be solving? could she be solving? could we be solving? could you be solving? could they be solving?
Perfect	V-ing perfect
could I have solved? could you have solved? could she have solved? could we have solved? could you have solved? could they have solved?	could I have been solving? could you have been solving? could she have been solving? could we have been solving? could you have been solving? could they have been solving?

Interro-negative form

Simple form	V-ing form
could I not solve? could you not solve? could she not solve? could we not solve? could you not solve? could they not solve?	could I not be solving? could you not be solving? could she not be solving? could we not be solving? could you not be solving? could they not be solving?
Perfect	V-ing perfect
could I not have solved? could you not have solved? could she not have solved? could we not have solved? could you not have solved? could they not have solved?	could I not have been solving? could you not have been solving? could she not have been solving? could we not have been solving? could you not have been solving? could they not have been solving?