Learn Hardcore Japanese: sinnyuusyain ga tyourei de mizikai supiiti wo site, minna ni zikosyoukai wo sita. - A new employee gave a short speech at the morning assembly and introduced herself to everyone.

新入社員が:
- が marks the grammatical subject and often just reports a fact or describes what happened.
- It can feel like: “(The) new employee (is the one who) did X.”
- Common when you’re just narrating an event or answering “What happened?”
新入社員は:
- は marks the topic: what the sentence is about.
- It can feel like: “As for the new employee, (he/she) did X.”
- Often used when the new employee is already known in the conversation and you want to say something about them.

In this sentence, with が, it sounds like a neutral description of an event: a new employee gave a speech and introduced themselves at the morning assembly.

You could say 新入社員は朝礼で… if you want to make “the new employee” the ongoing topic of the paragraph or conversation.

Why is it 朝礼で and not 朝礼に?

The particle choice reflects the function:

で is used for:
- The place where an action happens (location of an activity)
- e.g. 学校で勉強する (study at school), レストランで食べる (eat at a restaurant)
に can be:
- A point in time: 9時に始まる (start at 9)
- A destination/goal: 学校に行く (go to school)
- A location of existence (with いる / ある): 学校にいる (be at school)

Here, 朝礼 (morning assembly) is treated like an event/place where an action is performed, so you mark it with で:

朝礼でスピーチをする = give a speech at the morning assembly.

Using 朝礼にスピーチをする is unnatural; で is the natural choice here.

Why is it スピーチをして? How does noun + を + する work?

In Japanese, you can turn many nouns into verbs with をする:

勉強をする → to study
料理をする → to cook
練習をする → to practice
スピーチをする → to give a speech

So スピーチをする literally means “to do a speech”, but in natural English we say “to give a speech”.

In the sentence, it’s in the て-form:

スピーチをして → “(having) given a speech / giving a speech and then…”

So スピーチをして just means “give a speech (and then…)”.

Why is there スピーチをして and 自己紹介をした? Isn’t a self-introduction already a kind of speech?

Yes, a self-introduction is a kind of speech, but the Japanese adds both for clarity and nuance.

短いスピーチをして: describes the form: the new employee gave a short speech.
みんなに自己紹介をした: describes the content/purpose: in that speech, they introduced themselves to everyone.

So it’s like saying:

“The new employee gave a short speech at the morning meeting and (in it) introduced themselves to everyone.”

Japanese often uses two noun+する verbs like this to show both the action type and its content/purpose.

What is the function of the て-form in スピーチをして、みんなに自己紹介をした?

The て-form (して) is used here to link two actions:

スピーチをして
みんなに自己紹介をした

The main uses of the て-form in this context:

Sequence of actions
- First action, then second action:
  スピーチをして、自己紹介をした。
  → “(He/she) gave a speech and (then) introduced themselves.”
Soft connection without stressing order too much
- It can also be read more like “and” without strong emphasis on which happened first.

Here, it naturally suggests:

The new employee gave a short speech, and as part of that or following that, introduced themselves.

The て-form keeps the sentence flowing without repeating the subject or tense.

Why is it みんなに and not みんなを or みんなは?

The particle に marks the target or receiver of an action.

みんなに自己紹介をした
→ literally: “did a self-introduction to everyone” → natural English: “introduced themselves to everyone.”

Compare:

に: target/receiver
- 先生に質問をした (asked the teacher a question)
- 友だちにメールを送った (sent an email to a friend)
を: direct object, the thing being acted on
- 友だちを紹介した (introduced my friend [to someone])
は: topic marker
- みんなは優しいです (As for everyone, they’re kind.)

So here, みんな is the audience receiving the introduction, so に is correct.

Why is there no “he/she/they” in the Japanese sentence?

Japanese often omits pronouns (I, you, he, she, they) when they are clear from context.

The subject is marked by 新入社員が (the new employee).
Once that’s said, you usually don’t repeat “he/she” in Japanese if it’s obvious who is acting.

So instead of:

“The new employee, he gave a short speech and he introduced himself to everyone.”

Japanese naturally just says:

新入社員が…スピーチをして、自己紹介をした。
→ The subject “new employee” is understood for both verbs.

If the subject had already been introduced in previous sentences, even 新入社員が might be omitted and you might just see:

朝礼で短いスピーチをして、みんなに自己紹介をした。

Why is the verb ending した (past tense)? Does this mean the whole sentence is in the past?

Yes. した is the plain past form of する (“to do”).

する → do
した → did

In:

スピーチをして、みんなに自己紹介をした

the final verb is した (past), so the whole sentence is understood as past tense. The て-form before it (して) is like a non-finite form; its time reference is controlled by the final verb.

So:

スピーチをして、自己紹介をした → “gave a speech and introduced themselves” (past)
スピーチをして、自己紹介をする → “(will) give a speech and introduce themselves” or “(usually) gives a speech and introduces themselves” depending on context.

How would this sentence look in a more polite style?

Right now it uses plain past (した). In a polite context (e.g. news, formal writing, someone narrating politely), you would use ます-forms:

新入社員が朝礼で短いスピーチをして、みんなに自己紹介をしました。

Changes:

した → しました (polite past)
して stays as て-form of します: して

Everything else remains the same.

Can the word order be changed, like 朝礼で新入社員が短いスピーチをして…?

Yes. Japanese word order is relatively flexible as long as the particles are correct. Some possible orders:

新入社員が朝礼で短いスピーチをして、みんなに自己紹介をした。
朝礼で新入社員が短いスピーチをして、みんなに自己紹介をした。
新入社員が短いスピーチを朝礼でして、みんなに自己紹介をした。

All are grammatically OK. The differences are in emphasis and flow:

Putting 朝礼で earlier can emphasize the setting (at the morning assembly).
Putting 新入社員が earlier emphasizes who did the action.

However, the original word order is very natural and neutral.

Does 新入社員 mean one specific new employee or all the new employees? Is it singular or plural?

Japanese nouns usually don’t show singular vs plural by form alone. 新入社員 could mean:

“the new employee” (one person)
“the new employees” (a group)

Which one it is depends on context:

If the company hired only one new person, it likely means that one person.
If many new people joined and the sentence is about one of them, sometimes Japanese would say ある新入社員 (“a certain new employee”) or otherwise make it clear.
If it’s clearly about a group (e.g. photo of several people all speaking one by one), it could be read as plural.

With no further context, English translations usually pick one: “The new employee gave a short speech…” because that’s a common situation (each new hire gives a self-intro speech).