〜まま
Leaving things as they are, still unchangedmachine translation
FormationVerb た-form・ない-form／い-adjective／な-adjective + な／Noun + の + まま
〜まま describes a state that is kept unchanged while something else happens: テレビをつけたまま寝てしまった (I fell asleep with the TV still on). When two actions pair up like this, the sentence usually implies that the state is abnormal — it should have been changed — a point exams love to test.
Connection: verbs use the た-form (つけたまま) or ない-form (食べないまま), い-adjectives stay as is (古いまま), な-adjectives add な (不便なまま), nouns add の (昔のまま). The phrases このまま・そのまま (just like this/that) are used on their own and are extremely common.
Don't confuse it with 〜ながら (N4): ながら is two ACTIONS happening in parallel (音楽を聞きながら勉強する), while まま is one static STATE serving as the backdrop for an action (靴を履いたまま入る — entering with shoes still on). Compared with 〜ずに・ないで (doing B without doing A), ない-form + まま emphasizes that the "not yet/never happened" state persists throughout: 何も食べないまま一日が終わった.
Examples
テレビをつけたまま、寝てしまいました。
I fell asleep with the TV still on.
靴を履いたまま、部屋に入らないでください。
Please don't come into the room with your shoes still on.
この町は、昔のままで何も変わっていない。
This town is just as it was in the old days — nothing has changed.