つく

The Japanese verb つく (点く) is a fundamental intransitive verb primarily used to describe the state of a light, fire, or electronic device becoming active or being lit. In the context of Japanese grammar, being an intransitive verb means that the action happens to the subject itself, often without a direct agent being emphasized in the sentence structure. For English speakers, this is most closely translated as 'to turn on,' 'to be lit,' or 'to catch fire.' It is essential to distinguish this from its transitive counterpart, つける (点ける), which is used when someone actively turns something on. When you use つく, you are focusing on the result or the state of the object rather than the person who flipped the switch. This word is ubiquitous in daily Japanese life, appearing in conversations about household chores, urban environments, and even metaphorical descriptions of brightness.

Core Meaning

The spontaneous or resulting state of illumination or ignition. It describes the moment a dark room becomes bright or a cold stove becomes hot.

Understanding the nuance of つく requires a grasp of Japanese 'state-of-being' logic. If you walk into a room and the light is already on, or if you are observing the lights flickering to life at dusk, つく is your go-to verb. It is used for electricity-based items like lamps, televisions, and computer screens, as well as combustion-based items like gas stoves, matches, and candles. For instance, if you are trying to light a match and it finally ignites, you would exclaim, 'Hi ga tsuita!' (The fire caught!). This highlights the successful transition from 'off' to 'on' or 'unlit' to 'lit'.

Common Subjects

Electricity (denki), Lights (akari), Gas (gasu), Fire (hi), Matches (matchi), and Screens (gamen).

In a broader sense, つく can also be used for electronic devices that show a sign of life. If your phone screen suddenly glows in the dark, you would say 'Gamen ga tsuita.' It implies a sense of activation. This is particularly useful when troubleshooting; if a device is broken, you might say 'Denki ga tsukanai' (The power won't come on/The light won't turn on), indicating a failure in the state transition. This simplicity makes it one of the most useful verbs for beginners to master early in their Japanese studies.

Cultural Nuance

In Japanese culture, there is a strong emphasis on the natural flow of events. Using intransitive verbs like 'tsuku' allows the speaker to describe the world as it unfolds, rather than always centering human agency, which can sometimes sound too forceful or direct.

Using つく correctly involves understanding its grammatical placement as an intransitive verb. The basic sentence pattern is [Subject] ga tsuku. Because it is intransitive, you never use the object particle 'o' (を) with it. If you find yourself wanting to say 'I turned on the light,' you must switch to the transitive verb tsukeru. However, if you are describing the light itself performing the action of turning on, つく is the correct choice. This distinction is vital for achieving natural-sounding Japanese.

The 'Ga' Particle

The particle 'ga' marks the subject that is undergoing the change. For example, 'Denki ga tsuita' (The light turned on). Using 'wa' is also possible for thematic emphasis, but 'ga' is standard for reporting a new observation.

The verb conjugates like a standard Group 1 (U-verb). Its polite form is tsukimasu, and its past tense is tsuita. When talking about something that 'won't turn on' (indicating a malfunction), the negative form tsukanai is used. This is frequently heard when people are frustrated with technology or appliances. Additionally, the 'te-form' tsuite can be used to describe a state of being currently on when combined with iru (tsuite iru), though usually, the simple past tsuita is used to describe the completed action of turning on.

Conjugation Examples

Dictionary: tsuku | Polite: tsukimasu | Negative: tsukanai | Past: tsuita | Te-form: tsuite.

Another important usage is in conditional sentences. For example, 'Kuraku nattara, denki ga tsukimasu' (When it gets dark, the lights will turn on). Here, つく describes a predictable outcome of a condition. It is also used with adverbs like pika-tto (with a flash) to add descriptive flavor: 'Denki ga pika-tto tsuita' (The light turned on with a flash). This helps create a more vivid picture in the listener's mind, a common feature of Japanese expressive language.

Common Adverbs

Yatto (finally), Totsuzen (suddenly), Jidouteki-ni (automatically), Patto (suddenly/brightly).

You will encounter つく in a variety of everyday scenarios in Japan. One of the most common places is within the home. Imagine a family member coming home and noticing the living room is dark; they might ask, 'Nande denki ga tsuite nai no?' (Why isn't the light on?). Or, if a child is trying to use a toy that requires batteries, they might complain to their parent, 'Denki ga tsukanai yo!' (The light won't turn on!). These domestic interactions are the bread and butter of this verb's usage.

In the Kitchen

When using a gas range, you might hear 'Gasu ga tsuita' once the blue flame appears. If it's an old stove that's hard to light, someone might say 'Nakanaka tsukanai' (It just won't light).

Outside the home, つく is frequently used in public spaces. In Japanese cities, streetlights (gaitou) and neon signs (neon sain) are iconic. As evening falls, you might hear someone remark on how the city is 'lighting up' using this verb. Public transportation also uses it; for example, when a bus or train's 'stop' light (tomarimasu botan) illuminates after a passenger presses it, that action is described by つく. It signifies that the system has acknowledged the input and is now active.

Public Spaces

Streetlights turning on at 6 PM, vending machine displays lighting up, or the 'In Use' light on a restroom door.

In the digital world, つく applies to the screens of our devices. If you are watching a livestream and the 'Live' indicator turns on, or if your laptop screen wakes up from sleep mode, つく is used. It's also used in gaming; for instance, when a specific status light on a controller turns on to show which player you are. The word carries a sense of 'readiness' or 'activation' that is essential for navigating modern technology in a Japanese-speaking environment.

Digital Contexts

Smartphone screens, 'On Air' lights in studios, notification LEDs, and dashboard lights in cars.

The most frequent mistake English speakers make with つく is confusing it with its transitive pair つける (tsukeru). In English, the phrase 'turn on' can be both transitive ('I turn on the light') and intransitive ('The light turns on'). In Japanese, these are strictly separated. If you say 'Denki o tsuita,' it is grammatically incorrect because つく cannot take a direct object. You must say 'Denki ga tsuita' or 'Denki o tsuketa.' Remembering that つく is about the object's state will help you avoid this pitfall.

Transitive vs. Intransitive

Tsuku (Intransitive): Focuses on the light. Denki ga tsuku. | Tsukeru (Transitive): Focuses on the person. Denki o tsukeru.

Another common error is homophone confusion. Japanese has many words pronounced tsuku, each written with different kanji. 付く means 'to be attached' or 'to come with' (like a side dish), 着く means 'to arrive' (at a destination), and 突く means 'to poke' or 'to stab.' If you are writing, using the wrong kanji can completely change the meaning of your sentence. In casual text, many people stick to hiragana to avoid this, but in formal writing, using 点く is specific to lighting and fire.

Homophone Trap

Tsuku (点く): To light up. | Tsuku (着く): To arrive. | Tsuku (付く): To attach. | Tsuku (突く): To poke.

Furthermore, learners sometimes use つく for things that don't 'light up' in the traditional sense. For example, you wouldn't use つく for turning on a water faucet (that's dasu or hineru) or opening a book. It is strictly for things involving electricity, light, or fire. Using it for a radio is acceptable because it involves 'turning on' the power, but for mechanical things like a bicycle or a door, it is inappropriate. Understanding the 'energy' aspect of つく is key to its correct application.

Scope of Use

Limited to: Lights, Screens, Gas, Fire, Electricity. Not for: Water, Air (usually), Mechanical movement.

While つく is the most common way to say something turns on, there are several other words that can be used depending on the specific context or the level of formality. Understanding these alternatives will help you sound more like a native speaker and allow you to describe scenes with greater precision. For example, if you want to emphasize that a room became bright rather than just the light turning on, you might use akaruku naru (to become bright).

Tsuku vs. Akaruku naru

Tsuku focuses on the device/source (The lamp turned on). Akaruku naru focuses on the environment (The room became bright).

In more technical or formal settings, you might encounter tentou suru (点灯する). This is a Sino-Japanese compound (kango) that literally means 'to light a lamp.' You'll see this on control panels, in manuals, or hear it in formal announcements. For fire specifically, moeru (燃える - to burn) or hi ga okoru (火が起こる - fire arises) are alternatives. Moeru describes the ongoing state of burning, whereas つく describes the initial moment of ignition.

Formal Alternatives

Tentou suru (点灯する): Formal/Technical for 'light turns on'. | Chakka suru (着火する): Formal for 'ignition/catching fire'.

For electronic devices like computers or engines, kidou suru (起動する - to start up/boot) is a common alternative. While you can say the screen つく, the entire process of the system starting is kidou. Similarly, for a heater or air conditioner, you might use ugoku (動く - to move/work) to indicate it has started functioning. However, つく remains the most versatile and simple way to describe the 'on' state for anything that emits light or heat.

Device-Specific Words

Kidou (起動): Booting up a PC. | Ugoku (動く): An appliance starting to work. | Kakaru (かかる): An engine starting.