Breakdown of dengen wo kiranai to, gamen ga akarui mama desu.
ですdesu
to be
をwo
direct object particle
がga
subject particle
とto
conditional particle
ままmama
as is; state
明るいakarui
bright
〜ない〜nai
negative form
画面gamen
screen
電源dengen
power
切るkiru
to turn off
Elon.io is an online learning platform
We have hundreds of Japanese lessons and thousands of exercises.

Questions & Answers about dengen wo kiranai to, gamen ga akarui mama desu.
What function does と have in 電源を切らないと?
In this sentence, と attached to the plain negative verb 切らない creates a conditional meaning “if” (or “unless”). So 電源を切らないと means “if you don’t turn off the power.” This と often describes an automatic or inevitable result, rather than a one‐time hypothetical.
Why is the verb form 切らない in the plain style, while the main clause ends with polite です?
Conditionals with 〜と always use the plain (dictionary) form of the verb—affirmative or negative—regardless of the politeness level of the main clause. It’s common in Japanese to mix plain in subordinate clauses (like conditionals) with polite in the main clause. Hence 電源を切らないと (plain) + 画面が明るいままです (polite).
What does まま mean in 画面が明るいままです?
The noun まま indicates that a state remains unchanged. Here 明るいままです literally means “(it) is in the state of being bright,” i.e. “the screen stays bright.” You use まま after adjectives or verbs to say “as is” or “still in that condition.”
Why is が used in 画面が明るいまま instead of は?
が marks 画面 as the grammatical subject of the adjective 明るい (“bright”). Using は (画面は明るいままです) would shift the topic and add contrast or emphasis (“As for the screen, it stays bright”), which slightly changes the nuance. Here the speaker simply states what remains bright.
Why is there no verb like なる after まま? Why just ままです?
まま itself is a noun meaning “the state as is,” so pairing it with the copula です is enough to describe that state. Adding なる (“become”) would instead describe a change into that state, which isn’t the intended meaning here.
Could I say 電源を切らないまま、画面は明るいです instead?
Yes, that’s grammatically possible: 電源を切らないまま画面は明るいです means “the power stays on and the screen is bright.” It emphasizes the continuing state rather than a condition‐result warning. If you want to give a caution or instruction (“if you don’t turn it off, then… ”), 切らないと is more natural.
What’s the difference between using と and たら in this conditional?
Both can mean “if,” but と often signals a general, natural, or inevitable consequence, while たら is more flexible and can imply one‐time or hypothetical events. Here, 電源を切らないと feels like “whenever you don’t turn it off, (the screen will inevitably stay bright).” Using たら (切らなかったら) wouldn’t be wrong, but it might feel slightly more “If it happens that you don’t turn it off, then…” rather than a routine.
How do you attach まま to different types of words (i-adjectives, na-adjectives, verbs)?
• After i-adjectives: use the plain form + まま
e.g. 明るいまま, 寒いまま
• After na-adjectives or nouns: add のまま
e.g. 静かなまま, 部屋のまま
• After verbs: use the dictionary (or negative) form + まま
e.g. 電源を切らないまま, ドアを開けたまま