Warning, this verb may not exist. Conjugation is given as example.
Affirmation
Simple form
I could write write you could write write he could write write we could write write you could write write they could write write
V-ing form
I could be write writing you could be write writing he could be write writing we could be write writing you could be write writing they could be write writing
Perfect
I could have write writed you could have write writed he could have write writed we could have write writed you could have write writed they could have write writed
V-ing perfect
I could have been write writing you could have been write writing he could have been write writing we could have been write writing you could have been write writing they could have been write writing
Negation
Simple form
I couldn't write write you couldn't write write he couldn't write write we couldn't write write you couldn't write write they couldn't write write
V-ing form
I couldn't be write writing you couldn't be write writing he couldn't be write writing we couldn't be write writing you couldn't be write writing they couldn't be write writing
Perfect
I couldn't have write writed you couldn't have write writed he couldn't have write writed we couldn't have write writed you couldn't have write writed they couldn't have write writed
V-ing perfect
I couldn't have been write writing you couldn't have been write writing he couldn't have been write writing we couldn't have been write writing you couldn't have been write writing they couldn't have been write writing
Interrogative form
Simple form
could I write write? could you write write? could he write write? could we write write? could you write write? could they write write?
V-ing form
could I be write writing? could you be write writing? could he be write writing? could we be write writing? could you be write writing? could they be write writing?
Perfect
could I have write writed? could you have write writed? could he have write writed? could we have write writed? could you have write writed? could they have write writed?
V-ing perfect
could I have been write writing? could you have been write writing? could he have been write writing? could we have been write writing? could you have been write writing? could they have been write writing?
Interro-negative form
Simple form
couldn't I write write? couldn't you write write? couldn't he write write? couldn't we write write? couldn't you write write? couldn't they write write?
V-ing form
couldn't I be write writing? couldn't you be write writing? couldn't he be write writing? couldn't we be write writing? couldn't you be write writing? couldn't they be write writing?
Perfect
couldn't I have write writed? couldn't you have write writed? couldn't he have write writed? couldn't we have write writed? couldn't you have write writed? couldn't they have write writed?
V-ing perfect
couldn't I have been write writing? couldn't you have been write writing? couldn't he have been write writing? couldn't we have been write writing? couldn't you have been write writing? couldn't they have been write writing?