Learn Hardcore Japanese: huzaihyou wo mite, takuhaibin no kaisya ni denwa wo simasita. - I saw the missed-delivery slip and called the courier company.

Full form (if you split it into two clauses):
不在票を見て、（私は）宅配便の会社に電話をしました。
“(I) saw the missed-delivery notice and then called the courier company.”

Here:

不在票を = direct object of 見る
見て = て-form of 見る, used to connect to the next action
電話をしました = main verb phrase of the sentence

Even though 見る is in て-form (見て), it is still a full verb, so it still takes its normal object with を. The て-form just means “this action connects to the next one.”

What does the 〜て in 見て mean here? Is it “and”, “after”, or “because”?

The て-form can express several related ideas: sequence, cause, or just linking actions. In this sentence it’s mainly:

Sequence / weak cause: “After seeing / On seeing / When I saw (the slip), I called …”

Natural English translations could be:

“After seeing the missed-delivery slip, I called the courier company.”
“When I saw the missed-delivery slip, I called the courier company.”

All of these are better than a flat “I saw it and I called…”, because the seeing clearly leads to the calling. Japanese often uses 〜て for this “first A happened, so then I did B” feeling, without making the cause super explicit.

So here 見て is “having seen / after seeing / on seeing,” lightly implying reason as well as order.

Could I say 不在票を見たから、宅配便の会社に電話をしました instead? What’s the difference from 不在票を見て…?

You can say it, and it’s natural, but there’s a nuance difference:

不在票を見て、宅配便の会社に電話をしました。
- Neutral storytelling: first I saw it, then I called.
- Cause is implied but not strongly stressed.
不在票を見たから、宅配便の会社に電話をしました。
- から explicitly marks a reason: “Because I saw the slip, I called…”
- It emphasizes the logical cause-and-effect a bit more.

So:

〜て: “(Having) done X, I did Y” → light sequence/connection.
〜たから / 〜たので: “because I did X, I did Y” → clearer, stronger reason.

In casual speech, people often use 〜て exactly like this sentence to imply “so then I…”, especially when the cause is obvious from context. Both versions are correct; which you pick depends on how strongly you want to state the “because.”

What does 宅配便（たくはいびん） mean, and how is it different from 宅急便 or 配達?

宅配便
- 宅 = home
- 配 = deliver
- 便 = service
  → 宅配便 = “home-delivery parcel service,” i.e. a courier company that brings packages to your home (Yamato, Sagawa, etc.).
  In English, “courier service / delivery service / parcel delivery” is close.
宅急便（たっきゅうびん）
This is actually a brand name of Yamato Transport (Kuroneko). Strictly speaking, it’s like saying “FedEx” instead of “courier,” but many people use it generically in conversation.
配達（はいたつ）
This just means delivery in general (newspaper delivery, pizza delivery, mail delivery, etc.). It’s the act of delivering, not specifically a courier company.

In your sentence, 宅配便の会社 is basically “the delivery company / the courier company” that left the 不在票.

Why is there a の between 宅配便 and 会社?

の here makes 宅配便 modify 会社:

宅配便の会社 = “a company of宅配便” → “a courier (delivery) company”

This XのY pattern can mean:

possession: 田中さんの本 = Tanaka’s book
type/kind: 日本の会社 = a Japanese company
relationship: 学生のアルバイト = a part-time job (done) by a student

In this case, 宅配便 is specifying the type of company: a “home-delivery parcel” company.

Natural English: we would just say “the delivery company”, but Japanese often says “Xの会社” instead of turning X into an adjective.

Why do we use に after 会社 in 宅配便の会社に電話をしました?

With 電話する, the person or organization you call is marked with に:

Xに電話する = “to call X (on the phone)”

Examples:

友だちに電話しました。 = I called my friend.
会社に電話してください。 = Please call the company.
お母さんに電話した？ = Did you call your mom?

So in your sentence:

宅配便の会社に = “to the delivery company” (as the target)
電話をしました = “made a phone call”

The pattern is:

[Target]に　電話（を）する

You don’t use を after the person; を here belongs to 電話 (the act of calling), not to the company.

What’s the difference between 電話をしました, 電話しました, and 電話をかけました?

They’re very close in meaning; differences are mostly nuance and style.

電話をしました
- Polite: “(I) made a phone call.”
- 電話 is the object; する is the verb.
- Very common, slightly “fuller” sounding than dropping を.
電話しました
- Also polite, and just as correct.
- The を is simply omitted (which is very common in Japanese).
- Feels a bit lighter and more colloquial, but still standard.
電話をかけました
- Literally “(I) placed a phone call.”
- Emphasizes the act of placing/dialing a call.
- Often used when the focus is “I tried calling” (even if no one answered):
  - 会社に電話をかけたけど、誰も出ませんでした。
    “I called the company, but no one answered.”

In your sentence, any of these would work:

宅配便の会社に電話をしました。
宅配便の会社に電話しました。
宅配便の会社に電話をかけました。

The first two are the most neutral. The third slightly highlights the action of dialing.

Why are there two を particles in one sentence? Does that mean there are two direct objects?

There are two clauses, each with its own verb, so each を belongs to a different verb:

不在票を見て、…
- 不在票を = object of 見る
… 電話をしました。
- 電話を = object of する

The sentence is really:

(私は) 不在票を見て、 (私は) 電話をしました。

Japanese often chains clauses like this with the て-form and a comma. Each clause can have its own を, に, etc. That doesn’t mean a single verb has two direct objects; it means you have multiple verb phrases in one sentence.

Who is the subject in this sentence? There’s no “I” written.

Grammatically, the subject is omitted. Japanese very frequently leaves out the subject when it’s obvious from context.

In English we must say “I/you/he/she…”, but Japanese often doesn’t:

Context might be: you’re telling a friend what you did today. So it’s understood as “I”:
- “(私は) 不在票を見て、宅配便の会社に電話をしました。”
- “(I) saw the slip and called the courier company.”

Depending on the situation, it could also be “we,” “my wife,” “my roommate,” etc. Japanese relies heavily on shared context, so pronouns are added only when needed to avoid confusion or to emphasize who did it (e.g. 私が, 彼が).

How polite or formal is this sentence? Where could I use it?

The sentence uses 〜ました, which is the standard polite (丁寧) past tense:

電話をしました = polite past
Plain (casual) past would be 電話をした

Politeness level:

Suitable for:
- talking politely to someone you’re not close to
- reporting what you did to a coworker, teacher, etc.
- writing an email or a message in neutral polite style

In more casual conversation with friends/family, you’d naturally say:

不在票を見て、宅配便の会社に電話した。

In a very formal business setting, you might upgrade to humble or more formal language, e.g.:

不在票を確認して、宅配便の会社に電話いたしました。

Can I change the word order, like 宅配便の会社に、不在票を見て電話をしました? Is that okay?

Yes, that version is grammatical, and people might say it, but the original word order is a bit more natural.

Original:
不在票を見て、宅配便の会社に電話をしました。
→ First you state the trigger (“After seeing the slip”), then you say what you did and to whom (“I called the delivery company”).
Your variant:
宅配便の会社に、不在票を見て電話をしました。
→ “To the delivery company, having seen the slip, I called.”
The meaning is basically the same, but it feels a bit less smooth and slightly harder to process because 不在票を見て is inserted between 会社に and 電話をしました.

Japanese word order is flexible, but a common and natural pattern is:

[Reason/condition/time] + [object/target] + [verb]

So 不在票を見て、宅配便の会社に電話をしました。 is the most typical and easy-to-follow ordering.