English verb conjugation
COULD IMPROVE

Regular verb: improve - improved - improved

Affirmation

Simple form	V-ing form
I could improve you could improve she could improve we could improve you could improve they could improve	I could be improving you could be improving she could be improving we could be improving you could be improving they could be improving
Perfect	V-ing perfect
I could have improved you could have improved she could have improved we could have improved you could have improved they could have improved	I could have been improving you could have been improving she could have been improving we could have been improving you could have been improving they could have been improving

Negation

Simple form	V-ing form
I could not improve you could not improve she could not improve we could not improve you could not improve they could not improve	I could not be improving you could not be improving she could not be improving we could not be improving you could not be improving they could not be improving
Perfect	V-ing perfect
I could not have improved you could not have improved she could not have improved we could not have improved you could not have improved they could not have improved	I could not have been improving you could not have been improving she could not have been improving we could not have been improving you could not have been improving they could not have been improving

Interrogative form

Simple form	V-ing form
could I improve? could you improve? could she improve? could we improve? could you improve? could they improve?	could I be improving? could you be improving? could she be improving? could we be improving? could you be improving? could they be improving?
Perfect	V-ing perfect
could I have improved? could you have improved? could she have improved? could we have improved? could you have improved? could they have improved?	could I have been improving? could you have been improving? could she have been improving? could we have been improving? could you have been improving? could they have been improving?

Interro-negative form

Simple form	V-ing form
could I not improve? could you not improve? could she not improve? could we not improve? could you not improve? could they not improve?	could I not be improving? could you not be improving? could she not be improving? could we not be improving? could you not be improving? could they not be improving?
Perfect	V-ing perfect
could I not have improved? could you not have improved? could she not have improved? could we not have improved? could you not have improved? could they not have improved?	could I not have been improving? could you not have been improving? could she not have been improving? could we not have been improving? could you not have been improving? could they not have been improving?