English verb conjugation
COULD VANISH

Regular verb: vanish - vanished - vanished

Affirmation

Simple form	V-ing form
I could vanish you could vanish he could vanish we could vanish you could vanish they could vanish	I could be vanishing you could be vanishing he could be vanishing we could be vanishing you could be vanishing they could be vanishing
Perfect	V-ing perfect
I could have vanished you could have vanished he could have vanished we could have vanished you could have vanished they could have vanished	I could have been vanishing you could have been vanishing he could have been vanishing we could have been vanishing you could have been vanishing they could have been vanishing

Negation

Simple form	V-ing form
I couldn't vanish you couldn't vanish he couldn't vanish we couldn't vanish you couldn't vanish they couldn't vanish	I couldn't be vanishing you couldn't be vanishing he couldn't be vanishing we couldn't be vanishing you couldn't be vanishing they couldn't be vanishing
Perfect	V-ing perfect
I couldn't have vanished you couldn't have vanished he couldn't have vanished we couldn't have vanished you couldn't have vanished they couldn't have vanished	I couldn't have been vanishing you couldn't have been vanishing he couldn't have been vanishing we couldn't have been vanishing you couldn't have been vanishing they couldn't have been vanishing

Interrogative form

Simple form	V-ing form
could I vanish? could you vanish? could he vanish? could we vanish? could you vanish? could they vanish?	could I be vanishing? could you be vanishing? could he be vanishing? could we be vanishing? could you be vanishing? could they be vanishing?
Perfect	V-ing perfect
could I have vanished? could you have vanished? could he have vanished? could we have vanished? could you have vanished? could they have vanished?	could I have been vanishing? could you have been vanishing? could he have been vanishing? could we have been vanishing? could you have been vanishing? could they have been vanishing?

Interro-negative form

Simple form	V-ing form
couldn't I vanish? couldn't you vanish? couldn't he vanish? couldn't we vanish? couldn't you vanish? couldn't they vanish?	couldn't I be vanishing? couldn't you be vanishing? couldn't he be vanishing? couldn't we be vanishing? couldn't you be vanishing? couldn't they be vanishing?
Perfect	V-ing perfect
couldn't I have vanished? couldn't you have vanished? couldn't he have vanished? couldn't we have vanished? couldn't you have vanished? couldn't they have vanished?	couldn't I have been vanishing? couldn't you have been vanishing? couldn't he have been vanishing? couldn't we have been vanishing? couldn't you have been vanishing? couldn't they have been vanishing?