とおりに

The pattern とおりに (sometimes written in Kanji as 通りに) is used to emphasize that an action is being carried out in strict accordance with a specific model, instruction, or plan. It translates to 'just as,' 'exactly as,' or 'following.' The particle に is often optional. In fact, dropping the に is overwhelmingly common (often the default) in everyday and business Japanese, particularly when using the Noun + どおり pattern (e.g., 予定どおり進める（よていどおりすすめる - proceed as planned）). Note that in professional business and official government documents, it is highly recommended to write this grammar pattern in hiragana (とおり), reserving the kanji (通り) for physical streets.

1. Usage with Verbs:
When attaching to verbs, the tense indicates the timing of the model action:

• Dictionary Form: Used when the model action is about to happen or happens generally. (e.g., 'Do as I [am about to] say.')
• た form: Used when the model action has already occurred. (e.g., 'Do as I [already] said.')
• ている form: Used for ongoing states or knowledge (e.g., 知っているとおり（しっているとおり - as you know）).
• てある form: Used for referencing written instructions or established states (e.g., 書いてあるとおりに（かいてあるとおりに - exactly as it is written）).

Note: This pattern is almost exclusively used with affirmative verbs. Attaching it to negative verbs (e.g., 言わないとおり（いわないとおり）) is highly unnatural.

2. Usage with Nouns and Demonstratives:
There are specific rules for attaching to nouns and demonstratives:

• Noun + の + とおり(に): This is the standard connection, preferred for longer noun phrases or specific physical objects (e.g., 地図のとおり（ちずのとおり - just like the map）, 先生の教えのとおり（せんせいのおしえのとおり - exactly as the teacher taught）).
• Noun + どおり(に): When attached directly, the 「と」 sound changes to a 「ど」 sound (Rendaku). This acts as a suffix and is heavily preferred for short, two-kanji Sino-Japanese nouns like 予定（よてい - plan）, 期待（きたい - expectation）, and 計画（けいかく - plan）. This also applies to nouns derived from verbs, such as 思いどおり（おもいどおり - just as one thought/hoped） and 望みどおり（のぞみどおり - just as one wished）. Furthermore, Katakana loanwords frequently take this direct suffix (e.g., マニュアルどおり - exactly according to the manual, イメージどおり - just as imagined, ルールどおり - according to the rules). Exception: Words that point to parts of a document, such as 下記（かき - the following） or 右（みぎ - the above/right）, almost exclusively take のとおり (e.g., 下記のとおり). Saying 下記どおり is considered unnatural. Note on Interchangeability: For many nouns, both forms are grammatically acceptable (e.g., 予想のとおり（よそうのとおり） and 予想どおり（よそうどおり）). The difference is that the direct 〜どおり acts more like a fixed compound word, while 〜のとおり feels slightly more formal or emphasizes the noun.
• Demonstratives (この/その/あの): These attach directly without the particle の and without Rendaku (e.g., このとおり, そのとおり, あのとおり).

3. Sentence Variations:

• Predicate Usage: You can end a sentence with 〜とおりだ to say 'It is just as...' (e.g., 結果は予想どおりだ（けっかはよそうどおりだ - The result is just as predicted）).
• Adnominal Usage: Use 〜どおりの + Noun to modify a noun (e.g., 指示どおりの作業（しじどおりのさぎょう - work [done] according to instructions）).

4. Common Phrases and Negative Usage:
A very common set phrase is そのとおり (exactly like that / that's right). Highly frequent polite set phrases include ご覧のとおり（ごらんのとおり - as you can see） and ご存じのとおり（ごぞんじのとおり - as you know）. Additionally, this pattern is frequently used in the negative to express that things didn't go as planned, such as 思いどおりにいかない（おもいどおりにいかない - things don't go as one hopes/expects).

5. Nuance vs. ように:
While both can mean 'as,' とおりに implies 100% exactness. If you follow a recipe とおりに, you measure every gram perfectly. If you follow it ように, you are using it as a general guide or reference.