を: The Direct Object Marker | Japanese Grammar

を is the direct-object marker: it tags the thing that a transitive verb acts on — the thing eaten, read, drunk, watched, or made. If が answers "who does it?", を answers "does it to what?"

パンを食べる。

pan o taberu

[I] eat bread.

Two facts about を before we go further, because both are unusual. First, it is written with a dedicated kana, を, that in modern Japanese appears only as this particle — it is used for nothing else. Second, that kana is typed "wo" on any keyboard, but is pronounced "o", identical to the vowel お. So you type wo, you see を, and you say o. Every romanization on this page reflects the real sound: o, never wo. The spelling quirk gets its own page: は, へ, を as particles vs kana.

The basic job: the thing acted on

A transitive verb describes an action that lands on something — and that something takes を.

毎朝コーヒーを飲みます。

maiasa kōhī o nomimasu

I drink coffee every morning.

夜はテレビを見ます。

yoru wa terebi o mimasu

In the evening I watch TV.

日本語のニュースを読んでいます。

nihongo no nyūsu o yonde imasu

I'm reading the news in Japanese.

友だちに手紙を書いた。

tomodachi ni tegami o kaita

I wrote a letter to a friend.

In each case the を-noun is the thing directly affected, consumed, created, or perceived by the verb — coffee (drunk), TV (watched), news (read), a letter (written). English marks this with plain word order (verb + object, no preposition); Japanese marks it with を and lets word order stay flexible. The question word for a を-object is 何を ("what"):

昼ごはんに何を食べましたか。

hirugohan ni nani o tabemashita ka

What did you have for lunch?

Only transitive verbs take を

Here is the rule that actually governs を, and it is where English intuitions can mislead you: を appears only with transitive verbs — verbs whose action targets an external object. Intransitive verbs, which describe something happening by itself, take no を at all. Japanese takes this distinction far more seriously than English, because it stocks pairs of verbs, one transitive and one intransitive, from the same root.

Intransitive (happens by itself)	Transitive (someone does it)
ドアが開く (doa ga aku) — the door opens	ドアを開ける (doa o akeru) — [I] open the door
窓が閉まる (mado ga shimaru) — the window closes	窓を閉める (mado o shimeru) — [I] close the window
電気がつく (denki ga tsuku) — the light comes on	電気をつける (denki o tsukeru) — [I] turn on the light

風でドアが開いた。

kaze de doa ga aita

The door opened in the wind. (intransitive — no を)

寒いから、ドアを開けないで。

samui kara, doa o akenaide

It's cold, so don't open the door. (transitive — を)

The same English word "open" splits into two Japanese verbs, and the particle follows the verb: the door that opens on its own is the subject (が); the door that you open is the object (を). This is why you cannot decide on を just by looking at the noun — you have to know whether the verb is transitive. Mastering these pairs is one of the highest-value things a learner can do; they get a full page at transitivity pairs (自動詞／他動詞).

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Before you write を, check the verb, not the noun. If the verb describes something happening by itself (開く, 閉まる, 始まる, 止まる), it is intransitive and takes が. If it describes someone doing it to something (開ける, 閉める, 始める, 止める), it is transitive and takes を.

The を-phrase disappears constantly

Japanese is a pro-drop language: anything recoverable from context is left out, and objects are dropped even more freely than subjects. In real conversation, the を-phrase you would expect is often simply gone.

「このケーキ、食べる？」「うん、食べる。」

kono kēki, taberu? un, taberu

'Want some of this cake?' 'Yeah, I'll have some.'

The answer 食べる has no object at all, yet nobody is confused — the cake is right there. This is not an error or an abbreviation; it is how the language normally works. Do not feel obliged to supply an object every time your English translation has one.

Separately, in casual speech the を particle itself is frequently dropped even when the object is stated, especially in short questions:

コーヒー飲む？

kōhī nomu?

Want some coffee? (casual — を dropped)

This particle-dropping is informal register only. In neutral or polite speech, and always in writing, keep the を: コーヒーを飲みますか。 Recognize the dropped form when you hear it, but do not imitate it in a job interview.

Where を is a trap: が-predicates

A frequent English-transfer error is forcing を onto predicates that actually demand が. 好き (like), できる (can), 分かる (understand), ほしい (want), and 上手 (good at) all mark their "object" with が, because they describe states rather than actions.

日本の音楽が好きです。

nihon no ongaku ga suki desu

I like Japanese music. (好き takes が, not を)

Compare 音楽を聞く ("listen to music," a real transitive action → を) with 音楽が好き ("music is pleasing," a state → が). The verb 聞く acts on the music; the adjective 好き merely describes it. This whole stative class is worked out on が with 好き, ほしい, できる, 分かる.

The other を: motion through space

There is a second, distinct を that is not an object marker at all. With verbs of motion, を marks the space traversed — the path, road, or area you move through or along.

毎朝、公園を散歩します。

maiasa, kōen o sanpo shimasu

Every morning I take a walk through the park.

この道をまっすぐ行ってください。

kono michi o massugu itte kudasai

Go straight along this road, please.

散歩する (to stroll) and 行く (to go) are not doing anything to the park or the road — you are moving across them. This "path を" is a separate function that shares the same kana, and it has its own page: を of motion. For now, just be aware that seeing を after a place name does not automatically mean "direct object."

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A single clause normally allows only one を (the "double-を constraint"). This is why the path-を and an object-を rarely collide, and why causative sentences with two potential を-slots restructure to avoid the clash. If you find yourself wanting two を in one clause, one of them is in the wrong place.

Common mistakes

❌ ドアを開きました。（自分で開けた意味で）

Incorrect if you mean 'I opened the door' — 開く is intransitive (opens by itself); use the transitive 開ける.

✅ ドアを開けました。

doa o akemashita

I opened the door.

❌ お湯が沸かしました。

Incorrect — 沸かす is transitive and needs を for its object; が wrongly treats the water as the subject.

✅ お湯を沸かしました。

oyu o wakashimashita

I boiled the water. (沸かす is transitive → を; the intransitive 沸く takes が: お湯が沸いた 'the water boiled')

❌ 日本語をできます。

Incorrect — できる is stative and takes が, not を.

✅ 日本語ができます。

nihongo ga dekimasu

I can speak Japanese.

❌ 会議が始めます。

Incorrect — if a person starts the meeting, use transitive 始める with を; 始まる (intransitive) means the meeting starts on its own.

✅ 会議を始めます。

kaigi o hajimemasu

Let's begin the meeting.

❌ 昼ごはんに何が食べましたか。

Incorrect — the eaten thing is the object of transitive 食べる, so it takes 何を, not 何が.

✅ 昼ごはんに何を食べましたか。

hirugohan ni nani o tabemashita ka

What did you have for lunch?

Every one of these turns on the same axis: is the verb transitive or not? を belongs to genuine transitive verbs acting on an object. When the verb is intransitive (something happening by itself) you need が; when the predicate is stative (好き, できる) you also need が. Learn the transitivity of your verbs and を becomes automatic.

Key takeaways

を marks the direct object of a transitive verb — the thing acted on, consumed, created, or perceived.
Written with its own dedicated kana を, typed "wo", always pronounced "o".
Only transitive verbs take を. Intransitive verbs (開く, 閉まる, 始まる) describe events happening by themselves and take が.
Objects — and, in casual speech, the を itself — are dropped freely when clear from context.
Stative predicates (好き, できる, 分かる, ほしい) take が, not を.
A second を marks motion through space (公園を散歩する) and is not an object marker.

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