The Particle を: The Direct Object 直接目的語を示す「を」
The particle を is the second most important case particle in Japanese after the particle が. As we learned, case particles attach to a noun to mark a particular grammatical function (case). The function that the particle を marks, as we will learn, is to mark the direct object of a sentence. The grammatical case that it represents is called the accusative case (対格).
Before we get into the actual grammar of all this, let’s recap some important terminology that we have seen thus far while adding these new concepts to the list.
- Case Particle: A particle that attaches to a noun to mark a particular grammatical function/case.
- Verb: A word that describes an action, state, or occurrence. It may constitute the predicate at the end of a sentence or be part of a noun-predicate when used as a participle/modifier.
- Predicate: The part of a sentence that makes a statement about the subject.
- Intransitive Verb: A verb that only takes a subject and does not take an object.
- Transitive Verb: A verb that takes both a subject and an object.
- Object: A noun that is directed by the main verb of the sentence.
- Direct object: A word that receives the action of the main verb of the sentence.
- Accusative Case: Grammatical case whose main function is to show the direct object of a verb.
Pronunciation Note: The particle を is pronounced as “o” by most speakers, but it is historically pronounced as “wo,” which is still preferred in some dialects and certain social contexts. For instance, it is frequently pronounced as “wo” in clearly enunciated speech as well as in music.
What is a Direct Object?
直接目的語とは？
First, a direct object is a noun phrase denoting a person or thing that is the recipient of the action of a transitive verb. Putting aside what a transitive verb is, below are examples of direct objects in English.
i. I kissed a boy.
ii. I ate a hamburger.
iii. I drank milk.
iv. She bought a television.
v. He sold his stereo.
Intransitive vs Transitive
自動詞 vs 他動詞
The next question is what a transitive verb is, but in figuring this out, it is best to understand what transitive and intransitive verbs are.
Intransitive Verb: A verb that does not need an object to complete its meaning.
Transitive Verb: A verb that requires one or more objects to complete its meaning.
Here are some examples of both intransitive and transitive verbs in English.
vi. I saw a monkey. (transitive)
vii. He stood still. (intransitive)
viii. He found a raccoon. (transitive)
ix. The alligator swam away. (intransitive)
x. She cooked the meal. (transitive)
In Japanese, intransitive verbs are called 自動詞. Such verbs only require that a subject be used in concert with the predicate, and of course, the subject is marked by が. Transitive verbs are called 他動詞. Such verbs require that both a subject and direct object be used in concert with the predicate. Although the subject is still marked by が, the direct object is marked by を. The fact that 他動詞 need one more element (argument) to the sentence to be grammatical, the presence of a direct object or lack thereof, is frequently used to distinguish 自動詞 and 他動詞.
In fact, it is often the case that the subject of an intransitive predicate can become the direct object of a transitive predicate. This is also the case in English, which can be seen in the following examples.
1. 電気がついた。(Intransitive)
The lights turned on.
2. ジェイムズさんが電気をつけました。(Transitive)
James turned on the light.
Note how the subject of Ex. 1 is the direct object of Ex. 2. Likewise, the subject of Ex. 3 is the direct object of Ex. 4.
3. ビールが冷えた。(Intransitive)
The beer chilled.
4. 雄太君がビールを冷やした。(Transitive)
Yuta chilled the beer.
Intransitive-Transitive Verb Pairs
自動詞と他動詞のペア（自他のペア）
In English, the verbs “to turn on” and “to chill” can be both used as either intransitive or transitive verbs without any change to their conjugations; however, the same cannot be said for Japanese. “To turn on” is つく and つける for the intransitive and transitive sense respectively, and “to chill” is 冷える and 冷やす in the intransitive and transitive sense respectively.
In Japanese, many verbs have intransitive-transitive verb pairs, which is another means of figuring out when and when not to use the particle wo を. Some of the most common examples of these so-called intransitive-transitive verb pairs in Japanese are listed below. Note that for some of them, they also create verb pairs in English.
| Definition | Intransitive | Transitive |
| To break | 壊れる | 壊す |
| To change | 変わる | 変える |
| To start | 始まる | 始める |
| To stop | 止まる | 止める |
| To open | 開く | 開ける |
5. 車が止まった。
The car stopped.
6. 警察官が僕の車を止めた。
A police officer stopped me (my car).
7. 窓が開いた。
The window opened.
8. 悠さんは窓を開けました。
Yu opened a/the window.
Usages of the Particle を
「を」の使い方
So far, we have seen how the particle を primarily marks the direct object, but that is not all it can do. を can be explained as having two broad purposes with various applications. Depending on the usage, you may see it with transitive verbs, intransitive verbs, or both. For this lesson, we will only see how it is used with transitive verbs as a direct object marker.
The Direct Object Marker を
The basic usage of を is to mark the direct object of a transitive verb. Not all transitive verbs in English are transitive verbs in Japanese, and so you cannot always expect を to be the correct particle to choose, but for verbs that are unequivocally transitive.
9. 机を売る。
To sell a desk.
10. 床を掃く。
To sweep the floor.
11. 雑誌を読む。
To read a magazine.
12. お好み焼き1を食べる。
To eat okonomiyaki.
13. テレビを見る。
To watch TV.
14. オレンジジュースを飲む。
To drink orange juice.
15. 勝利を目指す。
To aim for victory.
16. 漢字を勉強する。
To study kanji.
17. 石を投げる。
To throw (a) rock(s).
18. お湯2を沸かす。
To boil water.
- お好み焼き is known as the Japanese pancake. In its predominant form, the batter is made of 小麦粉 (flour), grated 長芋 (Chinese yam), 出汁 (soup stock), 玉子 (eggs), and 千切りキャベツ (shredded cabbage). Other ingredients such as 青ネギ (green onion), 肉 (meat), タコ (octopus), イカ (squid), エビ (shrimp), 野菜 (vegetables), コンニャク (konjac), 餅 (sticky rice cake), and チーズ (cheese) are typically added. ↩︎
- お湯 (hot water) is used instead of 水 (water) with the verb 沸かす (to boil). ↩︎