Warning, this verb may not exist. Conjugation is given as example.
Affirmation
Simple form
I could isle isle you could isle isle she could isle isle we could isle isle you could isle isle they could isle isle
V-ing form
I could be isle isling you could be isle isling she could be isle isling we could be isle isling you could be isle isling they could be isle isling
Perfect
I could have isle isled you could have isle isled she could have isle isled we could have isle isled you could have isle isled they could have isle isled
V-ing perfect
I could have been isle isling you could have been isle isling she could have been isle isling we could have been isle isling you could have been isle isling they could have been isle isling
Negation
Simple form
I could not isle isle you could not isle isle she could not isle isle we could not isle isle you could not isle isle they could not isle isle
V-ing form
I could not be isle isling you could not be isle isling she could not be isle isling we could not be isle isling you could not be isle isling they could not be isle isling
Perfect
I could not have isle isled you could not have isle isled she could not have isle isled we could not have isle isled you could not have isle isled they could not have isle isled
V-ing perfect
I could not have been isle isling you could not have been isle isling she could not have been isle isling we could not have been isle isling you could not have been isle isling they could not have been isle isling
Interrogative form
Simple form
could I isle isle? could you isle isle? could she isle isle? could we isle isle? could you isle isle? could they isle isle?
V-ing form
could I be isle isling? could you be isle isling? could she be isle isling? could we be isle isling? could you be isle isling? could they be isle isling?
Perfect
could I have isle isled? could you have isle isled? could she have isle isled? could we have isle isled? could you have isle isled? could they have isle isled?
V-ing perfect
could I have been isle isling? could you have been isle isling? could she have been isle isling? could we have been isle isling? could you have been isle isling? could they have been isle isling?
Interro-negative form
Simple form
could I not isle isle? could you not isle isle? could she not isle isle? could we not isle isle? could you not isle isle? could they not isle isle?
V-ing form
could I not be isle isling? could you not be isle isling? could she not be isle isling? could we not be isle isling? could you not be isle isling? could they not be isle isling?
Perfect
could I not have isle isled? could you not have isle isled? could she not have isle isled? could we not have isle isled? could you not have isle isled? could they not have isle isled?
V-ing perfect
could I not have been isle isling? could you not have been isle isling? could she not have been isle isling? could we not have been isle isling? could you not have been isle isling? could they not have been isle isling?