Learn Hardcore Japanese: ane mo syuumatu dake sono resutoran de arubaito wo simasu. - My older sister also works part-time at that restaurant only on weekends.

Use 姉 when referring to your own older sister in a neutral or formal context.
- Example: 姉は学生です。 – My older sister is a student.
Use お姉さん:
- when talking about someone else’s older sister (polite), or
- when addressing your own older sister directly (like “sis”).
Use 妹 (いもうと) when you’re talking about your younger sister (again, usually for your own family member; 妹さん for someone else’s).

So in this sentence, 姉 is “my older sister,” not “younger sister,” and it’s not being used to address her directly.

What is the role of も in this sentence, and how is it different from は?

も means “also / too / as well” and marks something as in addition to something mentioned earlier.

姉も… implies:
- Someone else has already been mentioned as doing a part-time job there on weekends (e.g. I do, or my brother does), and
- My older sister also does the same thing.

Difference from は:

姉は週末だけそのレストランでアルバイトをします。
Focuses on what the older sister does: “As for my older sister, she works part-time there only on weekends.”
姉も週末だけそのレストランでアルバイトをします。
Adds the sister to an existing group: “My older sister also works part-time there only on weekends.”

So も ties this sentence to the previous context.

What does だけ mean here, and what exactly is it limiting?

だけ means “only / just” and it limits what comes before it.

In 週末だけそのレストランでアルバイトをします, the だけ is attached to 週末, so it means:

“only on weekends” (not on weekdays, not every day).

If you moved it, the meaning would change:

週末だけそのレストランでアルバイトをします。
She works there only on weekends.
そのレストランだけでアルバイトをします。
She works only at that restaurant (now だけ limits そのレストラン).
アルバイトだけをします。
She only does part-time work (and nothing else).

In the given sentence, だけ restricts the time (週末), not the place or activity.

Why is で used after そのレストラン, and how is it different from に?

で marks the place where an action occurs.

そのレストランでアルバイトをします。
“(She) does part-time work at that restaurant.”

Main difference:

に often marks a destination or existence:
- 行きます → そのレストランに行きます。 – go to that restaurant.
- あります / います → そのレストランに人がいます。 – There are people in that restaurant.
で marks the location of an activity:
- 食べます → そのレストランで食べます。 – eat at that restaurant.
- 働きます → そのレストランで働きます。 – work at that restaurant.

Since アルバイトをします is an activity done at the restaurant, で is correct.

Why is it アルバイトをします instead of just アルバイトします? Is を necessary?

アルバイトをする is the “textbook” form: [noun] + を + する.

アルバイトをします。 – (She) does a part-time job.

In everyday speech, people often drop を in this pattern:

アルバイトします。 – perfectly natural in conversation.

So:

アルバイトをします and アルバイトします are both acceptable.
With を, it feels a bit more explicit / textbook-like.
Without を, it’s a bit more casual and common in speech.

Your sentence is just using the more explicit form.

What is the nuance of using アルバイト here instead of a verb like 働きます?

アルバイト (often shortened to バイト) usually means:

Part-time job, especially for students or side jobs.

Nuances:

アルバイトをします。
→ She has/does a part-time job (often suggests temporary or side work).
働きます。
→ She works (more general, can be full-time employment, career, etc.).

In this sentence:

そのレストランでアルバイトをします。
Suggests she works there as a part-time worker, likely a student job or side job, not necessarily a full career position.

Why is the verb します in the polite non-past form? Does it mean present, future, or habit?

Japanese polite non-past (like します) can cover:

Present habitual: something done regularly.
Near future / scheduled future: something that will happen.

In this sentence, context tells us it’s a habitual action:

(My older sister) works part-time there only on weekends.
→ Regular, repeating action.

If you said:

姉も週末だけそのレストランでアルバイトをしています。

that would sound more like:

She is (currently) working there part-time (ongoing state), or
She currently has a part-time job there (emphasizing the ongoing situation).

Both are possible, but します is a neutral statement of a habitual fact.

Can the word order be changed, like putting 週末だけ after そのレストランで? Does that change the meaning?

Japanese word order is fairly flexible as long as particles are correct. These are all grammatical and mean almost the same:

姉も週末だけそのレストランでアルバイトをします。
姉もそのレストランで週末だけアルバイトをします。
週末だけ姉もそのレストランでアルバイトをします。

The basic meaning (she also only works there on weekends) stays the same, because:

週末だけ is still modifying 週末 (weekends),
そのレストランで is still the place.

Differences are mainly in emphasis / flow:

Putting 週末だけ earlier highlights the time restriction more.
Putting そのレストランで earlier can make the place feel a bit more prominent.

But for a learner, you can treat them as essentially the same meaning.

There’s no explicit subject like “my” or “she” in the sentence. How do we know who the sentence is about?

Japanese often omits the subject when it’s clear from context.

In this sentence, 姉 is the subject:

姉も週末だけそのレストランでアルバイトをします。 → (My) older sister also works…

There’s no 私の (my) before 姉, but:

Family terms like 母, 父, 姉, 弟, etc., when used without a possessive, usually refer to the speaker’s own family member unless context says otherwise.
Pronouns like “she” or “he” are not used as often as in English; Japanese relies on context plus nouns like 姉.

So native speakers automatically understand this as “my older sister also …” from the use of 姉 and the broader context of the conversation.

Why is it そのレストラン and not このレストラン or あのレストラン?

この / その / あの all mean “this / that”, but they differ in distance and perspective:

このレストラン – “this restaurant (near me / the speaker).”
そのレストラン – “that restaurant (near you / the listener, or already known in the conversation).”
あのレストラン – “that restaurant (far from both, or just ‘that one over there’).”

In practice, その is also used for:

Something already mentioned in the conversation.
Something both people know about, even if it’s not physically near either of them.

So そのレストラン suggests “that restaurant we both know / we were talking about,” rather than one physically near the speaker.

Why doesn’t 週末 have a particle like に (週末に)? Is 週末だけ without に normal?

Yes, 週末だけ without に is normal.

With time expressions, Japanese often omits the particle (especially に) when the meaning is clear:
- 毎日学校に行きます。 → 毎日学校行きます。
- 明日映画を見ます。 (no に)

For 週末だけ:

週末だけそのレストランでアルバイトをします。
→ “(She) works part-time there only on weekends.” (natural)
週末にだけそのレストランでアルバイトをします。
→ Also possible; can sound a bit more pointed, like stressing “only on the weekends (and absolutely not on other days).”

So dropping に here is both grammatical and natural.

Is there any difference between アルバイト and バイト?

バイト is simply a shortened, casual form of アルバイト.

Meaning is basically the same: part-time job.
アルバイト:
- Slightly more formal,
- Common in written Japanese, textbooks, formal speech.
バイト:
- Very common in everyday conversation,
- Feels casual.

In your sentence, you could say:

姉も週末だけそのレストランでバイトをします。

and it would sound more conversational.

Could this sentence be written with kanji for some of the words, and would that change the meaning?

Yes, some words usually appear in kanji, but the meaning doesn’t change:

姉も週末だけそのレストランでアルバイトをします。
(as given, with 週末 already in kanji)
This is already pretty standard:
- 姉 – kanji
- 週末 – kanji
- そのレストラン – mix of kanji/kana/katakana
- アルバイト – katakana

You might see variations like:

お姉ちゃん (more casual/childlike) instead of 姉, but that would slightly change the tone (more intimate/family-like).

Switching between kana and kanji for words like 姉 / あね or 週末 / しゅうまつ doesn’t change the grammar or meaning, just readability and style.