Breakdown of watasi ga rusu ni site iru aida ni, haha ha heya wo souzisimasita.
Questions & Answers about watasi ga rusu ni site iru aida ni, haha ha heya wo souzisimasita.
私が marks 私 as the grammatical subject of the subordinate clause 私が留守にしている間に (“while I am away”).
- In Japanese, inside a clause like X が … 間に, the subject is usually marked with が, not は.
- が answers “who is doing / in this state?” → “I am the one who is away.”
- は marks the topic, and you normally don’t introduce an extra topic inside this kind of time clause.
You could say 私は留守にしている間に in some contexts, but it sounds more like you’re re‑topicizing 私 and can feel a bit awkward here. The natural pattern for this time clause is 私が留守にしている間に.
Here 母は marks 母 as the topic of the main clause:
母は部屋を掃除しました。
As for my mother, (she) cleaned the room.
- は often introduces what the sentence is “about.”
- The subject of the action “cleaned the room” is already clear and un-contrasted, so は is more natural than が.
If you used 母が, it would sound more like you’re specifically identifying the doer, e.g.:
- 母が部屋を掃除しました。
“(It was) my mother (who) cleaned the room.” (perhaps in contrast to someone else)
In this sentence, the neutral, default way is 母は.
留守 (るす) is a noun meaning “absence (from home), being away.”
The usual pattern is 留守にする, literally “to make (something) into the state of absence,” which functions idiomatically as:
- 家を留守にする – “to be away from home”
In your sentence, we have:
- 留守にしている – the ている form of 留守にする
This expresses a continuing state: “(to be) in the state of being away.” So 私が留守にしている ≈ “while I am away (from home).”
There is a verb 留守をする, which also means “to be away (from home)”, but the pattern used here is 留守にする → 留守にしている.
This に comes from a common pattern:
[Noun] + に + する
“to make (something) into [that state]”
For example:
- 部屋を きれいにする – to make the room clean
- 静かにする – to make (something) quiet / to be quiet
Similarly:
- 留守にする – to make (it) “in the state of absence” → to be away (from home)
So in 留守にしている, the に is part of this “make it into that state” pattern. You can think of 留守にしている as “being in an absent/away state.”
Yes, you can say:
- 私が留守の間に、母は部屋を掃除しました。
This is very natural and means essentially the same thing.
Nuance:
- 留守の間に treats 留守 as a “state/noun”: “during the time of my absence.”
- 留守にしている間に describes the ongoing state more verb-like: “during the time when I am (being) away.”
In practice, both are acceptable and common. 留守の間（に） is a bit more compact and you’ll see it often in written Japanese (letters, signs, etc.).
Rough guideline:
- X している間 – “while X is happening” (two things happen continuously together)
- X している間に – “during the time that X is happening (something else happens at some point in that span)”
In your sentence:
- 私が留守にしている間に、母は部屋を掃除しました。
The mother’s cleaning is a bounded event that happened once (or over a limited period) within the time that the speaker was away.
That fits the typical use of 間に: something occurs at some point during a longer, continuous state.
You can say:
- 私が留守にしている間、母はずっと部屋を掃除していました。
“While I was away, my mother was cleaning the room the whole time.”
Here, both actions (being away, cleaning) are continuous, so 間 (without に) feels better.
In Japanese, the tense in a subordinate clause is often relative to the time of the main event, not to “now.”
- The main clause: 母は部屋を掃除しました → clearly past.
- The subordinate clause: 私が留守にしている間に describes a state that is ongoing at that past time.
So している here means “(am/was) in the state of being away at that time,” not present in relation to “now.”
You can say 私が留守にしていた間に; that also works. The nuance is very close, but:
- している間に is a kind of fixed pattern for “while (someone) is in that state.”
- Many speakers default to the non‑past 〜ている form in this kind of time clause, even when the overall sentence is past.
Both are grammatically acceptable; している間に just sounds very standard and natural.
The verb here is 掃除する (“to clean”), which typically takes the direct object with を:
- 部屋を掃除する – to clean (the) room
- 台所を掃除する – to clean the kitchen
So:
- 部屋を掃除しました。 – “(Someone) cleaned the room.”
Using 部屋が would normally not work here: 掃除する doesn’t take its target with が.
部屋に掃除する is also ungrammatical in standard Japanese. The cleaning “acts on” the room, so を is needed.
Japanese often omits possessives like “my/your/his” when they’re obvious from context.
In a sentence about your mother cleaning a room while you were away, the most natural assumption is:
- It’s your room.
So:
- 母は部屋を掃除しました。
is readily interpreted as “My mother cleaned my room.”
If needed, you can say:
- 母は私の部屋を掃除しました。
This explicitly states “my room,” which might be useful if there are multiple relevant rooms (e.g., mother’s room, sibling’s room, etc.). But in many everyday contexts, adding 私の is unnecessary.
Yes, that sentence is also natural:
- 母は、私が留守にしている間に、部屋を掃除しました。
Japanese word order is fairly flexible as long as:
- The verb comes at the end of the clause.
- Particles clearly mark the roles (が/は/を/に, etc.).
Both of these are fine:
- 私が留守にしている間に、母は部屋を掃除しました。
- 母は、私が留守にしている間に、部屋を掃除しました。
They mean the same thing; the difference is focus:
- Original: starts by setting the time frame first (“While I was away …”).
- Alternative: starts by introducing the topic/actor first (“As for my mother, while I was away, she cleaned the room.”)
Both are commonly used patterns.
Both forms exist:
- 掃除した / 掃除しました
- 掃除をした / 掃除をしました
掃除する is a suru-verb derived from a noun (掃除) plus する. With many such words:
- The を can be omitted in everyday usage:
- 勉強(を)する – to study
- 練習(を)する – to practice
- 掃除(を)する – to clean
Omitting を:
- Sounds a bit more compact and is very common, especially in speech.
- Is completely standard Japanese.
So 部屋を掃除しました is slightly more natural and concise than 部屋を掃除をしました, and that’s why the sentence uses 掃除しました.