Japanese De Particle Uses: Place, Means, Material, Cause, Scope and Totals

Place of action: resutoran de tabemasu

The first job of de is to mark the place where an action happens. Resutoran de tabemasu, I eat at a restaurant; toshokan de benkyō shimasu, I study at the library; eki de aimashō, let's meet at the station. The verb has to be something you do: eat, read, buy, wait, play, work, talk. If the verb only says that something exists or lives somewhere, the particle changes to ni, and the section on de versus ni below explains the line between them.

De also marks the event or occasion where something happens, not only a physical place: kaigi de hanashimashita, I spoke at the meeting; pātī de tomodachi ni aimashita, I met a friend at the party.

Means and tools: densha de, hashi de, Nihongo de

De marks the means by which an action is done, and that covers a wide field: transport, densha de ikimasu, by train; tools, hashi de tabemasu, with chopsticks; instruments, pen de kaite kudasai, please write in pen; languages, Nihongo de hanashimashō, let's speak in Japanese; and media, mēru de okurimasu, I'll send it by email.

Walking is the one transport that does not take de: aruite ikimasu, I go on foot, uses the te form of aruku. Everything else does, including bicycles, jitensha de, and taxis, takushī de. When you want to say you did something with somebody, that is to, not de: tomodachi to ikimashita. Tomodachi de would sound as if your friend were a vehicle.

Material and cause: ki de, kaze de

De marks the material something is made of when that material is still visible: ki de tsukutta isu, a chair made of wood; kami de tsuru o orimasu, I fold a crane out of paper. When the raw material has been transformed so that you cannot see it any more, kara takes over: kome kara sake o tsukurimasu, sake is made from rice.

De also states a cause, and this is the use that surprises learners most. Kaze de yasumimashita, I took the day off because of a cold; jishin de densha ga tomarimashita, the trains stopped because of the earthquake; shigoto de isogashii desu, I'm busy with work. The cause is always a noun, and it is something outside the speaker's control: weather, illness, accidents, workload. For a reason that involves a decision, Japanese uses a clause with kara or no de instead, and the no particle guide covers no de.

Scope: sekai de ichiban

When Japanese makes a superlative, it names the group first and marks it with de: sekai de ichiban takai yama, the highest mountain in the world; kurasu de ichiban se ga takai, the tallest in the class; Nihon de ichiban yūmei na machi, the most famous town in Japan. De sets the scope, the field within which the comparison is made.

The group can be a category rather than a place: kudamono de nani ga ichiban suki desu ka, which fruit do you like best? The answer keeps the shape: kudamono de wa ringo ga ichiban suki desu, with wa added to make the category the topic. The same scope de appears in kono naka de, among these, which is the phrase to reach for when someone shows you a menu or a set of choices.

Totals and time limits: zenbu de, ichi-jikan de

De after a quantity marks a total or a unit of counting. Zenbu de sen-en desu, it comes to a thousand yen in total; futari de ikimashita, the two of us went together; mittsu de happyaku-en, three for eight hundred yen. This is the de you hear at every register, and it answers the question zenbu de ikura desu ka, how much is it all together?

The same idea gives de after a length of time, meaning within or in that amount of time: ichi-jikan de owarimasu, I'll finish in an hour; go-fun de tsukimasu, we'll arrive in five minutes; ichi-nen de N3 ni gōkaku shimashita, I passed N3 in one year. Ichi-jikan on its own says how long the action lasted; de adds a boundary, the job fits within the hour.

De versus ni: the verb decides

The confusion that follows learners for years is de against ni for places. The rule is about the verb, not the place. If the verb describes an action carried out somewhere, use de: toshokan de yomimasu, I read at the library. If the verb describes existence, residence, arrival or a destination, use ni: toshokan ni imasu, I am at the library; Tōkyō ni sunde imasu, I live in Tokyo; eki ni tsukimashita, I arrived at the station.

A short list of ni verbs covers most cases: iru, aru, sumu, tsuku, iku, kuru, kaeru, oku, noru, suwaru, tomaru. Everything that is not existence, movement or placement takes de. The clearest pair is asobimasu and imasu: kōen de asobimasu, I play in the park; kōen ni imasu, I am in the park. Time is a separate matter: clock times and dates take ni, san-ji ni, and de never marks a point in time.

Summary table of de patterns

The table gathers the uses in one place with a model phrase for each, so you can check which pattern you are hearing.

Common mistakes with de

The first error is de with existence verbs: Tōkyō de sunde imasu should be Tōkyō ni sunde imasu, and heya de arimasu should be heya ni arimasu. The second is the reverse, ni with an action verb: toshokan ni benkyō shimasu should be toshokan de. The third is de for a companion: tomodachi de ikimashita means you went by means of your friend; use tomodachi to. The fourth is de after a point in time: san-ji de aimashō should be san-ji ni.

Two smaller slips are worth watching. Aruite de is a doubled means marker; aruite already means on foot. And de for a reason that is your own decision, tsukareta de yasumimashita, does not work; a clause needs kara or no de, tsukareta no de yasumimashita, while a noun cause takes de, tsukare de.

• Existence, living, arriving and placing take ni, not de
• Actions done somewhere take de, not ni
• Companions take to: tomodachi to, never tomodachi de
• Clock times and dates take ni, never de
• Walking is aruite, with no de after it
• A noun cause takes de; a clause reason takes kara or no de

If you want the wider comparison of ni and de across dozens of verbs, the dedicated post on ni versus de is the place to go; this article is the full map of de on its own.