ないnonexistent; not being (there); unowned; not had; unpossessed; unique; not; impossible; won't happen; to not be; …
I-adjective
なくてはwithout; unless; have to do
Expression
無くてはならないcannot do without something; indispensable; absolutely necessary; have to do
Expression
無くてはいけないcannot do without something; indispensable; absolutely necessary; have to do
Expression
無くてはいけませんcannot do without something; indispensable; absolutely necessary; have to do
Expression