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 couldn't isle isle you couldn't isle isle she couldn't isle isle we couldn't isle isle you couldn't isle isle they couldn't isle isle
V-ing form
I couldn't be isle isling you couldn't be isle isling she couldn't be isle isling we couldn't be isle isling you couldn't be isle isling they couldn't be isle isling
Perfect
I couldn't have isle isled you couldn't have isle isled she couldn't have isle isled we couldn't have isle isled you couldn't have isle isled they couldn't have isle isled
V-ing perfect
I couldn't have been isle isling you couldn't have been isle isling she couldn't have been isle isling we couldn't have been isle isling you couldn't have been isle isling they couldn't 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
couldn't I isle isle? couldn't you isle isle? couldn't she isle isle? couldn't we isle isle? couldn't you isle isle? couldn't they isle isle?
V-ing form
couldn't I be isle isling? couldn't you be isle isling? couldn't she be isle isling? couldn't we be isle isling? couldn't you be isle isling? couldn't they be isle isling?
Perfect
couldn't I have isle isled? couldn't you have isle isled? couldn't she have isle isled? couldn't we have isle isled? couldn't you have isle isled? couldn't they have isle isled?
V-ing perfect
couldn't I have been isle isling? couldn't you have been isle isling? couldn't she have been isle isling? couldn't we have been isle isling? couldn't you have been isle isling? couldn't they have been isle isling?