を (o): The Direct Object Particle

Level: N5. (Note: the JLPT publishes no official grammar list; the level shown is the common textbook convention.)

A particle is a short word placed after a noun to show its job in the sentence. を (o) is the object particle: it points at the thing the action is done to. 水を飲みます (Mizu o nomimasu) means “I drink water”, where 水 (mizu), “water”, is what gets drunk.

The rule

を (o) marks the direct object — the noun that directly receives the action of a transitive verb (a verb that acts on something, like eat, read, buy). The pattern is simple: object + を (o) + verb.

One quirk first: を (o) is written with its own kana but is pronounced “o”, exactly like the vowel お (o). Japanese keeps this kana only for the particle, so you will never see を (o) inside a normal word — seeing it tells you an object is right in front of it.

Beyond the plain object, を (o) does two more jobs with motion verbs:

• The space moved through or along. With 歩く (aruku, to walk), 通る (tōru, to pass), 飛ぶ (tobu, to fly) and 散歩する (sanpo suru, to stroll), を (o) marks the route: 公園を歩きます (Kōen o arukimasu) = “I walk through the park.”
• The point you leave or get off. With 出る (deru, to leave) and 降りる (oriru, to get off), を (o) marks the exit point: 家を出ます (Ie o demasu) = “I leave the house.”

Core uses of を (o)

Example sentences

Each sentence was written for this lesson, with readings.

Common mistakes

• ❌ 水が飲みます (mizu ga nomimasu) → ✅ 水を飲みます (Mizu o nomimasu). The thing drunk is the object, so it takes を (o), not が (ga).
• ❌ 寿司を好きです (sushi o suki desu) → ✅ 寿司が好きです (sushi ga suki desu). 好き (suki) marks what you like with が (ga), never を (o).
• ❌ 日本語を分かります (nihongo o wakarimasu) → ✅ 日本語が分かります (Nihongo ga wakarimasu). 分かる (wakaru) takes が (ga) for the thing understood.
• ❌ 公園で歩きます (kōen de arukimasu) for “walk through the park” → ✅ 公園を歩きます (Kōen o arukimasu). The route moved along takes を (o); で (de) would mean the park is just where some other action happens.
• ❌ 家で出ます (ie de demasu) → ✅ 家を出ます (Ie o demasu). The place you leave takes を (o), because 出る (deru) treats it as the exit point.

A short conversation

— 朝ご飯に何を食べますか。 (Asagohan ni nani o tabemasu ka.) — “What do you eat for breakfast?” — パンを食べて、コーヒーを飲みます。 (Pan o tabete, kōhī o nomimasu.) — “I eat bread and drink coffee.” — 今日は何時に家を出ますか。 (Kyō wa nan-ji ni ie o demasu ka.) — “What time do you leave the house today?” — 八時に出て、公園を歩いて駅に行きます。 (Hachi-ji ni dete, kōen o aruite eki ni ikimasu.) — “I leave at eight and walk through the park to the station.”

Usage notes

• Pronunciation. を (o) is always read “o”. Many textbooks romanise it “wo” to show the kana, but the sound is the same as お (o). On a keyboard you type “wo” to get を (o).
• One を (o) per verb. A clause normally has a single direct object: 私はパンを食べます (Watashi wa pan o tabemasu). The topic 私 (watashi) takes は (wa), and only the object takes を (o).
• Dropped in casual speech. In very casual conversation を (o) is sometimes dropped: ご飯食べた？ (Gohan tabeta?) = “Did you eat?” In writing and polite speech, keep it.
• する (suru) compounds. Many nouns become verbs with する (suru), and the noun can take を (o): 勉強をする (benkyō o suru) and 勉強する (benkyō suru) are both fine.

Compared with…

• が (ga) marks the subject (the doer or the thing described or liked), while を (o) marks the object (the thing acted on). 私がパンを食べます (Watashi ga pan o tabemasu): 私 (watashi) is the subject with が (ga), パン (pan) is the object with を (o). See the が (ga) subject particle lesson.
• で (de) marks the place where an action happens or the means used, not the thing acted on. 公園で遊びます (Kōen de asobimasu) = “I play in the park” (location of play), but 公園を歩きます (Kōen o arukimasu) = “I walk through the park” (route). See the で (de) particle lesson.

Quick recap before the quiz.

Practice

Quiz

Recap cheat-sheet

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