Breakdown of osoi zikan ni undou wo suru to, nemurenai kamo siremasen.
にni
time particle
時間zikan
time
とto
conditional particle
かも しれないkamo sirenai
might
運動 を するundou wo suru
to exercise
遅いosoi
late
眠れるnemureru
to be able to sleep
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Questions & Answers about osoi zikan ni undou wo suru to, nemurenai kamo siremasen.
Why is に used after 遅い時間?
The particle に marks a specific point in time when something happens (in this case, “at a late hour”). Without に, 遅い時間 would just be a noun phrase (“late time”) and wouldn’t function as “when” you do the action.
Could you say 夜遅く運動すると… instead of 遅い時間に運動をすると…?
Yes.
- 夜遅く運動すると眠れないかもしれません means roughly the same: “If you exercise late at night…”
- 遅い時間に is a bit more formal and a bit more general (“at a late hour”), whereas 夜遅く specifically emphasizes “late at night.”
What does the と after 運動をする do here?
That と is the conditional “if/when” particle. It connects the clause 運動をする to its natural consequence 眠れないかもしれません:
“If you exercise at a late hour, you might not be able to sleep.”
Why is there a comma after と?
Japanese often uses a comma (、) after a conditional と to separate the condition from the result for clarity. It’s optional and purely for readability; omitting it doesn’t change the meaning.
Why is it 眠れない instead of 眠られない?
Both are negative potential forms (“cannot sleep”), but:
- 眠れない is the standard, more common way.
- 眠られない feels stilted or overly passive.
Most native speakers use 眠れない in everyday speech and writing.
What exactly does かもしれません mean? How polite is it?
かもしれません expresses possibility: “might” or “perhaps.”
- It’s polite because of the -masu ending.
- Neutral/casual equivalent: かもしれない.
So 眠れないかもしれません = “you might not be able to sleep.”
In the example it’s written かも しれません with a space. Shouldn’t it be one word?
In modern Japanese it’s typically written as one set かもしれません, but grammatically it’s かも + 知れません (“it may be that … is known”). The spacing in your textbook probably just highlights the two parts; you can safely write かもしれません together.
Why is there no subject in the sentence? Who is doing the exercising?
Japanese often omits the subject when it’s obvious from context. Here it’s a general statement—“if one exercises (or you exercise) late at night…” The subject is understood rather than explicitly stated.
Can you drop the を in 運動をする and just say 運動する?
Yes. Both are acceptable:
- 運動をする (noun + を
- する)
- 運動する (verb form)
運動する is more concise and very common, especially in casual speech.