kanozyo ha daigaku ni kayoinagara, syuumatu ha kafe de arubaito wo simasu.

〜ながら means while doing ... or as ....

So 大学に通いながら means while attending/commuting to university. It shows that one action happens alongside another situation or activity.

A useful pattern is:

• verb stem + ながら

Examples:

• 音楽を聞きながら勉強する = study while listening to music
• 働きながら学校に通う = go to school while working

In this sentence, it suggests that attending university is an ongoing part of her life, and on top of that, she also works on weekends.

Because ながら attaches to the verb stem.

For 通う, the stem is 通い:

• dictionary form: 通う
• stem: 通い
• with ながら: 通いながら

This is the same pattern as:

• 食べる → 食べながら
• 読む → 読みながら
• する → しながら

So 通いながら is just the normal grammatical form of 通う before ながら.

With 通う, the place you regularly go to is usually marked by に.

So:

• 大学に通う = attend/commute to university
• 学校に通う = attend school
• 病院に通う = regularly go to a hospital/clinic

Here, に marks the destination or place one regularly goes to.

A learner might expect で, but で would not be natural with 通う in this meaning. 通う focuses on going to a place repeatedly, so に is the normal choice.

The first は in 彼女は marks the main topic: as for her.

The second は in 週末は also marks a topic, but here it has a contrastive feel:

• as for weekends
• on weekends, ...

So the sentence is structured like:

• As for her, while attending university, as for weekends, she works part-time at a café.

This second は helps separate one part of her routine from the rest of her life. It can imply something like:

• during the week she is a student
• on weekends, she works

Both can be possible in different contexts, but 週末は is very natural when talking about a habitual pattern or routine.

• 週末は = as for weekends / on weekends
• 週末に = on the weekend or at the weekend, often pointing more directly to a time

In this sentence, 週末は sounds like a general habit:

• On weekends, she works part-time at a café.

Using は also gives a slight contrastive nuance, which fits routines well.

で marks the place where an action happens.

So:

• カフェでアルバイトをします = does part-time work at a café

Compare:

• に often marks destination or existence
• で marks the location of an action

Examples:

• 図書館で勉強する = study at the library
• 日本で働く = work in Japan
• カフェでアルバイトをする = work part-time at a café

Both are possible, but they are slightly different.

• 働きます = work
• アルバイトをします = do a part-time job / work part-time

アルバイト specifically tells you the kind of work: part-time work.
So アルバイトをします is more specific than 働きます.

Also, in Japanese, many nouns combine with する:

• 勉強をする
• 運動をする
• アルバイトをする

In casual speech, people often drop を:

• カフェでアルバイトします

But with をします, the sentence sounds fully standard and polite.

Japanese non-past can cover:

• present habitual actions
• future actions

Here, します describes a habitual routine, not just one future event.

So it means she works part-time on weekends as a regular habit.

This is very common in Japanese:

• 毎日勉強します = I study every day
• 週末は出かけます = I go out on weekends

So even though the form is called non-past, here it is best understood as a repeated present habit.

Yes, but the nuance would change a little.

• アルバイトをします = she works part-time / that is her routine
• アルバイトをしています = she is doing part-time work / she is currently engaged in part-time work

In a sentence about someone’s regular schedule, します is very natural.
しています would put more emphasis on the ongoing state of being employed in that part-time job.

So for a simple statement of routine, します is often the better choice.

彼女は makes her the topic of the sentence: as for her.

If you used 彼女が, it would sound more like you are identifying or emphasizing she as the subject, often in contrast to someone else or as new information.

Compare:

• 彼女は大学に通いながら、週末はカフェでアルバイトをします。
  = As for her, she attends university and works part-time on weekends.

• 彼女が大学に通いながら、週末はカフェでアルバイトをします。
  = It is she who attends university and works part-time on weekends.
  This sounds less neutral in isolation.

So は is the natural choice for a normal descriptive sentence like this.

In this sentence, 週末 means weekends in general.

Japanese often does not mark singular vs. plural as clearly as English does. The broader meaning comes from context.

Because the sentence describes a routine, 週末は is naturally understood as:

• on weekends
• every weekend, depending on context

So even though English usually needs a plural idea here, Japanese does not need a special plural form.