Learn Hardcore Japanese: zyunbi ha yoteidoori ni susunde imasu. - The preparations are proceeding as planned.

は marks the topic: “As for the preparations…”
が marks the grammatical subject and often introduces/newly asserts information.
Both are possible, but the nuance differs:
- 準備は予定通りに進んでいます。 = Speaking about the preparations (topic), they’re proceeding as planned.
- 準備が予定通りに進んでいます。 = It’s the preparations (as opposed to something else) that are proceeding as planned, or as an answer to “What is going as planned?”

Why is に used after 予定通り? Can I drop it? Can I use で?

に turns 予定通り into an adverbial phrase: “in accordance with the plan.”
With this set expression, に can often be omitted: 予定通り進んでいます (both are common).
で is not used here; it would be ungrammatical in this pattern.
Similar patterns: 計画通り(に), 予想通り(に), 思った通り(に).

What exactly does 進んでいます express here?

Vている with verbs like 進む describes an ongoing state/result: “is in progress,” “is underway,” not necessarily someone actively doing it at this instant.
It’s about the status of the preparations rather than a momentary action.

Why is there no を after 準備? Isn’t 準備 the object?

進む is intransitive (“something advances/progresses”), so it does not take を.
If you want to show the actor actively pushing preparations forward, use the transitive pair:
- Status-focused: 準備が/は進んでいます。
- Actor-focused: （私たちは）準備を進めています。

Does 進んで mean “willingly” here?

No. Here 進んで is the て-form of the verb 進む plus います → 進んでいます (“is progressing”).
The adverb 進んで meaning “willingly/voluntarily” is a different usage: 彼は進んで手伝った。

Can I drop 準備は and just say 予定通りに進んでいます?

Yes, if the topic is clear from context. 予定通り(に)進んでいます。 is natural in a follow-up or status report.
Japanese often omits obvious topics; include 準備は when you need to establish or emphasize the topic.

Can I move 予定通りに elsewhere in the sentence?

Yes. Adverbials are flexible:
- 準備は予定通りに進んでいます。 (neutral)
- 予定通りに、準備は進んでいます。 (slight emphasis on “as planned”)
- 準備は、予定通りに進んでいます。 (pause/topic highlighting)
Meaning stays the same; choose what flows best in context.

What are the politeness/registration options for the predicate?

Why is it います and not です?

The predicate is a verb phrase (進んでいる), and ている uses いる/います.
です attaches to nouns/na-adjectives. If you switch structures you can use です:
- 準備は予定通りです。 (See next Q for nuance.)

Can I say 準備は予定通りです instead? What’s the nuance difference?

準備は予定通りです。 is natural and means “The preparations are as planned / on schedule,” focusing on conformity with the plan as a state.
準備は予定通りに進んでいます。 emphasizes the process/progression being on track.

What’s the difference between 予定通り, 計画通り, and スケジュール通り?

予定通り: default “as planned/on schedule”; very common and broad.
計画通り: “according to the plan (design/strategy).” Slightly more “plan content” than scheduling.
スケジュール通り: strictly time-schedule conformance. Use when talking about timetables.
All can pair with 進む: e.g., 工事は計画通りに進んでいます。

Is it 予定通り or 予定どおり? What about 予定のとおり?

Pronunciation is the same: “toori.”
Common and all correct:
- 予定どおり (kana for どおり; preferred by some style guides)
- 予定通り (kanji; very common)
- 予定のとおり (with の; a bit more explicit/formal)
Your sentence uses 予定通り; that’s perfectly fine.

How do I say it in the negative, past, or other tenses?

Are there natural alternatives to this wording?

準備は順調に進んでいます。 (smoothly)
準備の進捗は予定どおりです。 (noun “progress”)
準備を行っています。 (we are carrying out preparations; action-focused)
進行しています is fine for processes/events (e.g., 工事は進行しています), but 準備は進行しています sounds more formal/technical than typical status talk.
進捗しています is widely used in business; some prefer the noun: 進捗は順調です。

Who is actually doing the preparing? There’s no agent.

Japanese often omits the agent when it’s obvious or unimportant. The sentence reports status, not the doer.
If needed, specify with the transitive form:
- 私たちは準備を進めています。
- 運営側は準備を進めています。

Any reading/pronunciation tips for the words here?