There are many verbs (and nouns) in Japanese to describe when something gets changed or a change happens on its own. Looking at the subtleties of these verbs will help you determine how to use each one. The most common and broadly used verbs for change are 変える (kaeru) and 変わる (kawaru) which are different types of verbs and therefore have a difference in their usage.
変える (kaeru) and 変わる (kawaru) are both verbs which mean to change, but the difference is that 変える is a transitive verb in which a change is actively brought about by someone or something and 変わる is an intransitive verb in which a change comes about on its own without direct intervention.
Let’s look at both 変える (kaeru) and 変わる (kawaru) more closely. Below are more detailed definitions of both verbs as well as example sentences in which we will see that the transitive verb 変える takes the particle を (wo), and the intransitive verb 変わる takes the particle が (ga).
変える (kaeru)
Definition: (Transitive verb). Someone or something takes action to change something to a different state or changes the content of something from what it was before. Kanji Breakdown: 変 – change, strange Example Sentences: 本棚の場所を変えた。 I changed the location of the bookshelf. 世界を変えることは多くの起業家の夢です。 Changing the world is the dream of many entrepreneurs. 生活習慣を変えたかったので、朝早起きすることにしました。 I wanted to change my lifestyle, so I decided to start waking up early.
変わる (kawaru)
Definition: (Intransitive verb). Something changes in shape or appearance, or something changes from one state to another. Additional uses are to indicate a difference between two or more things, and to indicate that something or someone is strange or odd. Kanji Breakdown: 変 – change, strange Related Expressions: 気が変わる – to change one's mind 変わっている人 – an odd person Example Sentences: 風の向きが変わった。 The wind has changed direction. 子供が生まれた後、生活が大きく変わりました。 Since the birth of my child, my life has changed considerably. 車の型式によって、燃費効率が変わる。 Gas mileage varies depending on the model of the car. 消費者の好みが時代とともに変わっていく。 Consumer preferences change with the times. 事情が変わったので、戦略を変えないといけません。 Circumstances have changed, so we must change our strategy.
In the last example sentence for 変わる, both 変わる and 変える were used. Circumstances changed naturally, but in response a deliberate change of strategy was called for.
Japanese Nouns for Change: 変更 (henkou) and 変化 (henka)
変わる and 変える are godan verbs, but they can often be replaced by the related and slightly more formal nouns 変更 (henkou) and 変化 (henka) which share similar nuances and differences to their verb counterparts.
変更 (henkou) and 変化 (henka) are both nouns which mean change, but the difference is that 変更 means a change made by someone to something that was previously decided or established, and 変化 means a change from one state or property to another which occurred on its own without direct intervention.
変更 (henkou)
Definition: (Noun or participle which takes the auxiliary verb する (suru)). Someone makes a change to something that was previously decided or established. When used with する, 変更する is a transitive verb. Kanji Breakdown: 変 – change, strange 更 – renew, renovate Example Sentences: 予定を変更する。 To revise the schedule. 原案に次のような変更をしたいです。 I would like to make the following changes to the draft. ファイルを変更した場合は、必ず保存してから閉じてください。 If you make any changes to the file, be sure to save them before closing it.
変化 (henka)
Definition: (Noun or participle which takes the auxiliary verb する (suru)). Indicates a change from one state or property to another in which the change took place on its own. When used with する, 変化する is an intransitive verb. Kanji Breakdown: 変 – change, strange 化 – change, take the form of Example Sentences: ファッションは時代とともに変化します。 Fashion changes with the times. 技術の進歩により、社会は常に変化しています。 Society is constantly changing due to technological advances. ソーシャル メディアは、人々のコミュニケーション方法に多くの変化をもたらしました。 Social media has brought about many changes in the way people communicate.
Differences Between 代える, 替え, 換える
Let’s look at the differences between the verbs 代える, 替える and 換える all of which are homonyms and read as “kaeru”. These verbs are all transitive and each have their own cases in which they should be used, but it can be a challenge to differentiate between their nuances.
代える means to substitute. 替える means to replace. 換える means to exchange or to interchange. At a high level they all mean to change one thing for another thing, but the difference in nuance comes down to what is being changed and what purpose the new thing will serve in place of the original.
Before moving on to more detailed definitions and usages of each verb, it is important to note that these verbs are not used very often. Instead, they are commonly replaced by more precise terms which depend on what is being substituted/exchanged/replaced.
代える (kaeru)
Definition: (Transitive verb). To substitute. Often used to describe one person stepping in to take on the role of another. Also describes using something different as a stand-in for the original thing without necessarily needing it to be an exact replacement. Kanji Breakdown: 代 – substitute, change, convert, replace Example Sentences: お菓子作りをする時、砂糖をハチミツに代えることが多い。 I often substitute honey for sugar when I bake. 監督は試合の途中で選手全員を代えた。 The coach substituted all the players part way through the match.
In the two example sentences above, 代える could be replaced by equivalent terms. The first sentence could use the expression 代わりに (kawarini) which means ‘instead of’ or ‘as a substitute for’. The second sentence could use the noun 交代 which means ‘substitution’ or ‘relief’ for example, substituting players in sports or relieving guards from duty. The two new sentences would be:
お菓子作りをする時、砂糖の代わりにチミツを使うことが多い。 I often substitute honey for sugar when I bake. 監督は試合の途中で選手全員を交代させた。 The coach substituted all the players part way through the match.
替える(kaeru)
Definition: (Transitive verb). To replace something with something else of the same type. Often something old is replaced with something new. Usually used with inanimate things. Kanji Breakdown: 替 – exchange, substitute Example Sentences: 古いカーテンを替えた。 I replaced the old curtains. 車のタイヤを替えた方がいいよ。 The tires on your car should be replaced.
In the two example sentences above, 替える could be replaced by equivalent terms. Both sentences could use the compound verb 取り替える (torikaeru) which means ‘to exchange’ or ‘to replace’. Both could also use the highly versatile noun 交換 (koukan) with auxiliary verb する which means ‘exchange, substitution, replacement’. The new sentences could be:
古いカーテンを取り替えた。 I replaced the old curtains. 車のタイヤを交換した方がいいよ。 The tires on your car should be replaced.
換える (kaeru)
Definition: (Transitive verb). To exchange, as in giving one thing and receiving another in return, usually of the same value, and often of the same or similar type. Used with inanimate things. Kanji Breakdown: 換 – interchange, convert Example Sentences: 日本に行く前に、ドルを円に換えた。 I exchanged dollars for yen before going to Japan. 私は最初赤いシャツを買ったが、結局青いシャツに換えた。 I initially bought a red shirt, but I ended up exchanging it for a blue one.
In the two example sentences above, 換える could be replaced by equivalent terms. The first sentence could use the noun 両替 (ryougae) with auxiliary verb する which means ‘money exchange’. Interestingly, 両替 uses 替 rather than 換 in its kanji. The second sentence could once again use the noun 交換 (koukan) with する. The two new sentences would be:
日本に行く前に、ドルを円に両替した。 I exchanged dollars for yen before going to Japan. 私は最初赤いシャツを買ったが、結局青いシャツに交換した。 I initially bought a red shirt, but I ended up exchanging it for a blue one.
Differences Between 代わる, 換わる, and 替わる
Let’s look at the differences between 代わる, 換わる, and 替わる, all of which are homonyms and read as “kawaru”. As you may have guessed, like the case of 変える and 変わる, these verbs are all the intransitive counterparts of 代える, 換える, and 替える and have similar differences in nuance.
代わる means to be substituted. 替わる means to be replaced (something old for something new). 換わる means to be replaced (one thing for another thing of the same value). These verbs are similar, but difference in nuance comes down to what purpose the new thing serves in place of the original.
代わる (kawaru)
Definition: (Intransitive verb). To be substituted. Someone or something takes the place of the person or thing that was there before. Often used when one person takes over the role of a person who was serving the role previously. Kanji Breakdown: 代 – substitute, change, convert, replace Example Sentences: 勤勉に代わるものはありません。 There is no substitute for hard work. 人事異動で部長が新しい人に代わった。 The department head changed to a new person in a personnel reshuffle.
替わる(kawaru)
Definition: (Intransitive verb). Something is replaced with something else of the same type. Often something old is replaced with something new. Usually used with inanimate things. (Transitive verb). Two people switch positions. One person takes over for another when taking turns doing something. Kanji Breakdown: 替 – exchange, substitute Example Sentences: 真夜中に明日が今日に替わるとき、あなたはどんな気持ちですか？ How do you feel at midnight when tomorrow changes to today? 長い旅に、私たちは二時間おきに運転を替わる。 On long trips, we alternate as drivers every two hours.
替わるhas a couple peculiarities to take note of with respect to its second definition – the case of two people alternating in a role. One is that it is a transitive verb which takes the particle を. The other is that the meaning is similar to 代わる, but in the case of 替わる the switch could happen multiple times, whereas with 代わる the switch (substitution) is permanent.
換わる (kawaru)
Definition: (Intransitive verb). Something gets replaced with another thing of equal value, usually of the same or similar type. Used with inanimate things. Also has a nuance that once the replacement happens it is permanent. Kanji Breakdown: 換 – interchange, convert Example Sentences: 発泡容器に換わる生鮮食品の環境適合輸送資材はあるでしょうか？ [1] Are there environmentally compatible transportation materials for perishable food products that can replace foam containers? 置換品 とは、現在のアイテムに置き換わる製品のことです。[2] A replacement article is one in which an existing item is supplanted by a new one.
換わる is similar to the first definition of 替わる, but again the subtle nuance is that with 替わる the change could happen again, whereas with 換わる the change usually only happens once as a permanent change.
Final note. Ultimately, for the both verbs かえる and かわる the difference is often ambiguous between 換, 替 and 代 to the point that they are used interchangeably. As a sidestep, a writer may just choose to use hiragana to write them.
References:
[1] 長田 達明. (1996). 発泡容器に換わる生鮮食品の環境適合輸送資材. 食品の包装 = Packaging of foodstuff / 包装食品技術協会 編 27 (2).
[2] IBM. (2012). InfoSphere Master Data Management.