The Particle を: Marking the Direct Object

を has an easier job than most Japanese particles. It marks the thing a verb acts on, and for a beginner that's nearly the whole story. The trouble starts at the edges. 公園を歩く (walk through the park) has を but nothing an English speaker would call an object, and 猫が好き (I like cats) has an obvious object in English and no を.

It's written を and said お

In standard modern Japanese, を is pronounced exactly like お. 本を読む is "hon o yomu". You'll hear a clear "wo" now and then, in some songs, from some regional speakers, or when someone is spelling a sentence out very deliberately, but "o" is what to say. You do type it as "wo" on a keyboard, which is where the romanized name comes from.

The odd spelling is a leftover. Japanese spelling was reformed in 1946 so that kana would match how words were actually said, and を was replaced by お inside ordinary words. Before that, 男 (おとこ, man) was spelled をとこ. The reform made an exception for three particles, which kept their old kana: は said as "wa", へ said as "e", and を. So today を has essentially one use, and seeing it tells you an object has just gone by. That's handy in a language written without spaces.

The direct object

を goes straight after the noun that receives the action.

• パンを食べます。 (パンを たべます) I eat bread.
• 昨日、映画を見ました。 (きのう、えいがを みました) I watched a movie yesterday.
• 日本語を勉強しています。 (にほんごを べんきょうしています) I'm studying Japanese.
• 何を買いましたか。 (なにを かいましたか) What did you buy?

Because the particle labels the object, the object doesn't have to sit in a fixed position. 私は弟にその本をあげた and 私はその本を弟にあげた both mean "I gave that book to my younger brother." Each noun carries its own tag.

One restriction to know: Japanese avoids two を in the same simple clause. With a する verb you can say 日本語を勉強する or 日本語の勉強をする, but 日本語を勉強をする sounds wrong.

を as a clue to the verb

Japanese has many verb pairs where one takes an object and the other doesn't. ドアを開ける (ドアを あける) is "to open the door", something a person does. ドアが開く (ドアが あく) is "the door opens". Same with 電気をつける (でんきを つける, turn on the light) and 電気がつく (the light comes on). When you're unsure which verb of a pair you're looking at, the particle in front of it usually settles the question.

を with verbs of movement

This is the use that surprises people. Verbs like 歩く, 走る, 飛ぶ and 渡る don't act on anything, yet they take を. With these verbs, を marks the space the movement passes through or across.

Compare 公園を歩く with 公園で歩く. The first has you moving through the park, as on a walk that takes you across it. The second treats the park as the place where the activity of walking happens, the way you might walk laps there for exercise. Both are grammatical. を is the more usual choice when you're describing a route.

The place you leave

A second group of movement verbs uses を for the point of departure.

から can also mark a starting point, and for physical exits the two overlap: 部屋を出る and 部屋から出る both work for leaving a room. から puts more weight on the starting point itself. When the leaving is more abstract, as with graduating or quitting, を is the one that's used: 大学を出る can mean "to graduate from university", and 会社をやめる is "to quit the company".

Don't stretch this to destinations. Where you're going takes に or へ, never を. 学校に行く, not 学校を行く.

Where you'd expect を but get が

English speakers say "I like cats" and "I understand Japanese" and naturally reach for を. Japanese treats these as states, not actions, and marks the thing with が.

• 猫が好きです。 (ねこが すきです) I like cats. 好き is an adjective, closer to "cats are likable". 嫌い (きらい), 上手 (じょうず) and 下手 (へた) behave the same way.
• 日本語が分かります。 (にほんごが わかります) I understand Japanese.
• 新しい靴がほしい。 (あたらしい くつが ほしい) I want new shoes.
• ピアノができます。 (ピアノが できます) I can play the piano.

Potential forms and the たい form sit on the border. Textbooks teach 漢字が読める (かんじが よめる, I can read kanji) and 水が飲みたい (みずが のみたい, I want to drink water). In real usage 漢字を読める and 水を飲みたい are also common and accepted. If you write が with potential verbs you're on safe ground, and you shouldn't be thrown when you see を.

Even the "always が" words bend. You'll come across 彼のことを好きになった (I came to like him) and 気持ちを分かってほしい (I want you to understand how I feel), especially in longer sentences where が is already doing another job. Treat が as the rule for your own sentences and を as something you'll notice native speakers doing. Our post on は versus が goes further into what が is up to.

When を disappears

In casual conversation を is dropped all the time. ご飯食べた? (ごはん たべた) is "did you eat?" and 何してるの? (なに してるの) is "what are you doing?" Nothing is lost, since the object is right next to its verb. In writing, in polite speech and anywhere the sentence is long enough to be confusing, it stays.

を also vanishes when は or も takes over the object. To say you don't eat meat, with meat as the topic, it's 肉は食べません (にくは たべません), not 肉をは. "I also drink coffee" is コーヒーも飲みます. Other particles like に and で can stack with は and も (には, でも), but を gives way.

Set phrases built on を

A lot of everyday expressions are a noun, を and a verb that you wouldn't guess from English. They're best learned as whole units.

And the phrase you'll use most as a traveler: noun plus をください or をお願いします. 水をください (みずを ください) is "water, please." For where を sits among the other particles, see our overview of Japanese particles.

Common questions about を