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