How subordinate clauses and relative clauses work in Japanese

Subordinate clauses in Japanese are dependent clauses that add additional information to a main clause and cannot stand alone as complete sentences. They typically end with certain connecting forms such as -toki (when), -nagara (while), -kara (because), or conditional forms like -tara and -eba (if). These clauses provide context such as time, reason, condition, or simultaneous actions relative to the main clause. Importantly, subordinate clauses precede the main clause in Japanese, which follows a subject-object-verb (SOV) order. ¹

In practical terms, that means Japanese often builds up the background first and delivers the main event at the end. A sentence can describe when, why, or under what condition something happens before revealing the central action, which is one reason Japanese can feel “backloaded” to learners who are used to English.

Common subordinate-clause patterns include:

• Time: 昼ごはんを食べたとき、電話しました。
  “I called when I ate lunch.”
• Reason: 雨が降ったから、家にいました。
  “Because it rained, I stayed home.”
• Condition: 時間があれば、行きます。
  “If I have time, I’ll go.”
• Simultaneous action: 音楽を聞きながら、勉強します。
  “I study while listening to music.”

These endings are useful conversational signals because they tell the listener how to connect the background clause to the main statement. In speech, the intonation often stays suspended until the final verb of the main clause, so listening for the clause-ending form is a practical way to track the sentence structure.

Relative clauses in Japanese

Relative clauses in Japanese work by directly modifying a noun with a preceding clause that contains a verb. The modifying clause immediately precedes the noun it describes without needing relative pronouns like “who” or “which” in English. The verb in the relative clause is in a plain form and is linked directly to the noun. For example, “田中さんが旅行する北海道” means “Hokkaido where Tanaka-san will travel,” with the relative clause “田中さんが旅行する” directly modifying “北海道” (Hokkaido). Particles after the noun (such as は, を, に) help indicate the grammatical role of the noun in the overall sentence. ²

A more natural everyday example is:

• 昨日買った本 — “the book I bought yesterday”
• 友だちが作ったケーキ — “the cake my friend made”
• 日本に住んでいる人 — “a person who lives in Japan”

The key point is that Japanese does not insert a separate word equivalent to English “who,” “that,” or “which” in these cases. The noun appears after the full modifying clause, and the clause can describe not only people but also places, things, ideas, and even abstract situations.

Because the clause comes first, Japanese relative clauses often compress information efficiently. English may need two pieces of syntax—pronoun plus clause—while Japanese usually needs only the clause and the noun. This makes relative clauses very common in natural Japanese and especially important for reading and listening comprehension.

To summarize the differences and functions:

Relative clauses can use different verb forms, including causative or passive, to express nuances like letting someone do something or actions done upon the noun. The noun modified by the relative clause is often understood as the subject or object within that clause, depending on the context. ⁴

This flexibility is one reason Japanese relative clauses can feel tricky at first. The noun inside the clause is not always the thing doing the action. For example, in パーティーで会った人 (“the person I met at the party”), the noun 人 is the person being met, not the one doing the meeting. In passive examples such as 私が先生にほめられた本 (“the book I was praised for by the teacher”), the grammatical relationship has to be inferred from the sentence as a whole.

How to recognize each type while reading or listening

A useful way to separate the two is to ask whether the clause is modifying the whole sentence or a noun.

• If the clause ends in a connector like -kara, -toki, -tara, or -nagara, it is usually setting up the main clause.
• If the clause comes immediately before a noun, it is usually describing that noun.
• If the clause can be translated as “when,” “because,” “if,” or “while,” it is often subordinate.
• If the clause answers “which one?” or “what kind of person/thing?”, it is often relative.

Compare these two patterns:

• 雨が降ったから、出かけません。
  “Because it rained, I won’t go out.”
  The first clause explains the reason for the second.
• 雨が降った日に、出かけません。
  “On the day it rained, I won’t go out.”
  The clause modifies the noun 日 (“day”), so it functions like a relative-style modifier.

Japanese sometimes stacks multiple modifiers before a noun, so a noun phrase may contain time information, a description, and a relative clause all at once. The structure still follows the same principle: the modifying material comes first, and the noun appears at the end of the phrase.

Why this matters for conversation

In both subordinate and relative clauses, Japanese emphasizes a structure where modifying or dependent clauses come before what they modify, unlike English where relative clauses follow the noun.

That difference matters in real conversation because the listener often has to wait for the final verb to understand how all the earlier information fits together. A sentence like 来週東京に行く友だち can only be interpreted once the noun 友だち arrives at the end of the modifier, so processing Japanese in real time depends heavily on recognizing clause patterns quickly. Regular spoken practice helps make these clause shapes automatic, especially because they appear constantly in everyday directions, explanations, stories, and schedules.

Common mistakes

A few errors come up repeatedly:

• Putting the main verb too early.
  Japanese usually keeps the main action at the end of the sentence.
• Using a relative pronoun out of habit.
  English-style “who” or “which” is not normally used in Japanese relative clauses.
• Assuming the head noun is the subject of the relative clause.
  The noun may be the subject, object, or something else depending on context.
• Forgetting that the modifying verb is in plain form.
  Relative clauses generally use the dictionary/plain style rather than polite ます-form.

A useful habit is to identify the final noun or verb first: if a clause ends before a noun, it is probably modifying that noun; if it ends with a connector and then a comma, it is probably setting up the main clause.

Quick reference

• Subordinate clause: gives background such as time, reason, condition, or contrast.
• Relative clause: describes a noun directly.
• Japanese order: modifier first, main element later.
• No relative pronouns: the clause and noun connect directly.
• Plain form in modifiers: especially common in relative clauses.

This structure is one of the most important features of Japanese sentence building, and mastering it makes long sentences much easier to follow in reading and speaking.

References

• Japanese Clause: Definition, Grammar, Examples

• Japanese Relative Clauses

• Clauses

• Relative Clauses

• Clauses - japanese Grammar Guide

• Relative Clause Coordination and Subordination in Japanese

• Using descriptive subordinate clauses

• Japanese 101 Lesson 15 Relative Clauses

• Word order with subordinate clauses in Japanese.

• がある + Noun - Grammar Discussion