Learn Hardcore Japanese: titi ga nyuuinsite iru aida, haha ha mainiti manga to kudamono wo motte ikimasita. - While my father was hospitalized, my mother brought manga and fruit every day.

父が入院している間
Here, 父 is the subject of the state being hospitalized (入院している).
が marks the subject of that subordinate clause:
- 父が入院している = “(my) father is hospitalized.”
母は毎日漫画と果物を持って行きました
Here, 母 is the main topic of the whole action (the one doing the bringing).
は marks the topic:
- 母は … 持って行きました = “As for (my) mother, she brought …”

If you said 父は入院している間, it would be grammatically possible, but:

父は would then sound like the topic of the whole sentence, even though in this example the main story is about what the mother did.
Using 父が focuses more on the fact that “father is hospitalized” as a condition, while 母は presents “mother” as the topic doing the main action.

So:

父が → subject inside the “while …” clause.
母は → topic of the main sentence.

What exactly does 入院している mean here? Why not just 入院した or 入院中?

入院する means “to be hospitalized” / “to be admitted to a hospital.”

入院している is te-form + いる, which often expresses a continuing state resulting from some event.
Here it means “is (in the state of being) hospitalized,” i.e. “is in the hospital (as a patient).”

So:

父が入院している間
= “while my father was in the hospital / while he was hospitalized.”

Compare:

父が入院した間
This is unnatural. 入院した (simple past) describes the event of being admitted; combining that with 間 (“while”) clashes because "while" describes a span, not a punctual event.
父が入院中の間
This is grammatical but redundant: both 入院中 and 間 express “during/while.” You’d usually just say:
- 父が入院中、母は毎日…
  or
- 父が入院している間、母は毎日…

So 入院している nicely expresses “in the ongoing state of being hospitalized.”

What does 間 do here, and how is …間 different from …間に?

間 (あいだ) after a verb phrase means “while / during the time that …”

父が入院している間
= “while my father was in the hospital / during the period when he was hospitalized.”

Difference between 間 and 間に:

…間
Emphasizes that something continues throughout or over that whole period.
- 父が入院している間、母は毎日漫画と果物を持って行きました。
  → Throughout the time he was hospitalized, she did this every day.
…間に
Often used when an action happens at some point / one or a few times within that period, not necessarily continuously.
- 父が入院している間に、一度だけ大阪へ出張しました。
  → “While my father was hospitalized, I went to Osaka on a business trip (once).”

Here, because 母 was doing something regularly, every day, …間 is the natural choice.

Does 毎日 modify 母 (like “everyday mother”) or 持って行きました (like “brought [them] every day”)? How does that work?

毎日 is an adverb of time and it modifies the verb phrase 持って行きました, not 母.

母は毎日漫画と果物を持って行きました。
= “My mother brought manga and fruit every day.”

Japanese word order is more flexible than English, but:

Positioning 毎日 before the verb phrase (and after the topic 母は) is very natural:
- 母は　毎日　漫画と果物を　持って行きました。

You could also say:

母は漫画と果物を毎日持って行きました。

The meaning is essentially the same; 毎日 still modifies the action “brought (them).” It does not mean “an everyday mother.”

What does the と between 漫画 and 果物 mean here? Could we use や instead?

In 漫画と果物, と is a coordinating particle meaning “and (both A and B)”.

漫画と果物を持って行きました。
= “(She) brought manga and fruit (both of them).”

と usually lists all items, suggesting the list is complete.

If you used や:

漫画や果物を持って行きました。
This sounds like “(She) brought things like manga and fruit,” implying:
- The list is not exhaustive.
- There may have been other similar things she brought.

So:

と → “A and B” (specifically those).
や → “A, B, and things like that.”

The original sentence focuses on these particular two things, so と is appropriate.

Why is を used after 漫画と果物? What is it marking here?

を is the direct object marker.

漫画と果物を持って行きました。
→ 漫画と果物 are the things that were brought.

The verb is 持って行きました (“took/ brought [something] (to somewhere)”):

X を持って行く
= “to take/bring X (along / with you).”

So:

漫画と果物 = direct object (what she took).
を marks that role.

What exactly does 持って行きました mean? How is it different from just 持ちました?

持って行きました is a compound verb:

持つ = to hold / to have / to carry.
行く = to go.

In the te-form construction:

持って行く literally: “to go while holding/carrying [something].”
Idiomatically: “to take / bring [something] (to another place).”

So:

漫画と果物を持って行きました。
= “(She) took/brought manga and fruit (to him / to the hospital).”

If you used 持ちました alone:

漫画と果物を持ちました。
= “(She) held manga and fruit / had manga and fruit (in her hands).”

It does not by itself include the idea of going somewhere with them. That’s why 持って行く (bring/take along) is used here.

Could the parts of the sentence be rearranged? For example, can I say 母は、父が入院している間、毎日…?

Yes, Japanese allows some flexibility in word order, especially with adverbial phrases like time expressions.

Original:

父が入院している間、母は毎日漫画と果物を持って行きました。

Other natural variants:

母は、父が入院している間、毎日漫画と果物を持って行きました。
→ This is very natural; now the topic 母は appears first.
母は毎日、父が入院している間、漫画と果物を持って行きました。
→ Also possible, though the rhythm is a bit less smooth.

Key points:

The relative order of:
- the topic (母は),
- the time clause (父が入院している間),
- and the adverb (毎日)
can change without changing the core meaning.
The verb (here, 持って行きました) usually stays at or near the end.

All of these keep the same overall meaning; the slight changes are more about emphasis and natural rhythm.

Does 入院している間 mean the father is still in the hospital now, or does it only talk about the past?

In this sentence, the main verb is 持って行きました (past polite). That sets the time frame of the whole statement in the past.

父が入院している間、母は毎日…持って行きました。

Even though している is grammatically present progressive, it’s inside a past narrative. So it means:

“While my father was in the hospital, my mother brought … every day.”

It doesn’t, by itself, tell us whether the father is still in the hospital now. The sentence is just describing a past habit during that period.

If you wanted to clearly say he is still in the hospital and you are talking about an ongoing habit, you’d more likely use a present or present-progressive form for the mother’s action, such as:

父が入院している間、母は毎日漫画と果物を持って行っています。
→ “While my father is in the hospital, my mother is bringing manga and fruit every day.” (ongoing situation)

Is 入院する transitive or intransitive? Why is there no object like “hospital”?

入院する is an intransitive verb.

It literally combines 入る (to enter) + 院 (institution, hospital), but as a verb 入院する means:
- “to be hospitalized,”
- “to be admitted to the hospital as a patient.”

You do not say:

✕ 病院を入院する

Instead, you simply say:

父が入院する = “My father goes into the hospital / is hospitalized.”

If you want to explicitly mention the hospital, you might rephrase, for example:

父が病院に入院している
(still intransitive; 病院に marks the place associated with the hospitalization)

If I wanted to say “My mother visited my father in the hospital every day,” is 持って行きました the most natural verb? Or is there another word?

持って行きました focuses on what she brought (manga and fruit). It implies that she visited, but the emphasis is on bringing things.

If you want to emphasize visiting a sick person, Japanese often uses お見舞い (おみまい):

母は父を毎日お見舞いに行きました。
= “My mother went to visit my father (in the hospital) every day.”

To keep both ideas (visiting and bringing things), you could say:

父が入院している間、母は毎日お見舞いに行って、漫画や果物を持って行きました。
= “While my father was in the hospital, my mother went to visit him every day and brought things like manga and fruit.”

So:

持って行く → emphasizes bringing items.
お見舞いに行く → emphasizes the act of visiting a sick person.