する — To Do, To Make

Meaning & Usage

する (suru) is one of the two irregular verbs in Japanese — the other being くる (kuru, to come). Translated as "to do" or "to make," it covers far more ground than those English words suggest. Crucially, する combines with nouns to form a large category called する-verbs (サ変動詞, sa-hen doushi), drawing from Chinese loanwords, English borrowings, and native Japanese words alike.

English handles nouns and verbs with separate words: "study" (verb) vs. "a study session" (noun). Japanese handles it differently. The noun 勉強べんきょう (benkyou) means "study," and attaching する produces 勉強べんきょうする — "to study." That's it. The pattern works across hundreds of nouns, so each one you learn can double as a verb — no separate word required.

する reaches well beyond compound verbs. It describes sensations, sounds, smells, and feelings when combined with certain words. It also shows up in decision-making (にする — choosing something), cost (いくらする — how much does it cost?), and wearing accessories (ネクタイをする — wearing a tie). The scope surprises most beginners. Get comfortable with する early and a large portion of Japanese vocabulary starts to look familiar.

する also works across every register. Casual speech: 何なにする? (What are you doing?). Formal writing: 実施じっしする (to implement). Professional context: 発表はっぴょうする (to present). Even onomatopoeia: ドキドキする (heart pounding with nerves or excitement). Few verbs stretch this far.

Structure & Formation

する belongs to Group 3 alongside くる. Neither follows the standard Group 1 (う-verbs) or Group 2 (る-verbs) conjugation patterns — you need to memorize the forms directly.

The core structural patterns at N5 level:

• Noun + する — Creates a compound verb. Example: 電話でんわする (to telephone), 練習れんしゅうする (to practice)
• する (standalone) — Used as a general "to do" verb. Example: 何なにをしますか (What will you do?)
• Noun + に + する — Expresses a decision or choice. Example: コーヒーにします (I'll have coffee / I'll go with coffee)
• Onomatopoeia + する — Describes sensations. Example: ドキドキする (heart pounding), ふわふわする (feeling light/dreamy)

Example Sentences

Basic Usage: Everyday Actions

Noun + する Compound Verbs

にする — Making a Choice or Decision

Sensory and Feeling Expressions

Negative Forms

Common Mistakes

Mistake 1: Forgetting to Use する with Sino-Japanese Nouns

❌ 毎日、勉強。(Mainichi, benkyou.)

✅ 毎日まいにち、勉強べんきょうします。(Mainichi, benkyou shimasu.)

Nouns like 勉強べんきょう cannot function as verbs on their own. Attach する (or します in polite speech) to turn them into verbs. Dropping it produces a noun phrase, not a complete sentence. The rule is simple: Noun + する = Verb.

Mistake 2: Using を with する Compound Verbs That Already Contain an Object

❌ 勉強べんきょうを日本語にほんごをします。

✅ 日本語にほんごを勉強べんきょうします。

When a する-verb takes an external object, mark that object with を and attach する directly to the noun. Two を markers in one clause is ungrammatical. The noun inside the compound does not take its own を — only the external object does.

Mistake 3: Confusing にする with になる

❌ 医者いしゃにします。(Isha ni shimasu.) — intended to mean "I will become a doctor" ✅ 医者いしゃになります。(Isha ni narimasu.)

にする expresses a deliberate choice you are making (I'll go with X), while になる expresses change or becoming something. To say "I want to become a doctor," use になる. Reserve にする for situations where you are actively selecting among options — ordering food, choosing a color, picking a plan.

Mistake 4: Wrong Register — Using しない in Polite Speech

❌ 明日あしたはしない。(casual form used in a formal setting)

✅ 明日あしたはしません。(Ashita wa shimasen.)

Japanese has two main speech levels at N5: plain form and polite form (ます/です). With teachers, elders, customers, or strangers, use the polite forms: しません (negative), しました (past), します (present/future). Plain forms in formal settings read as rude or dismissive.

Mistake 5: Omitting が with Sensory する Expressions

❌ いいにおいをします。

✅ いいにおいがします。

When する describes a sensory perception — smell, sound, feeling — the subject takes が, not を. The sensation is something that occurs, not something being actively done. Examples: 音おとがする (a sound can be heard), においがする (there is a smell), 気きがする (I have a feeling that...).

Cultural Notes

する turns up in Japanese daily life in ways that often surprise English speakers. Japanese tends to frame emotions as active experiences rather than static conditions. Where English says "I am nervous," Japanese prefers ドキドキする or 緊張きんちょうする — the feeling is something happening to you right now, not a state you passively occupy.

In professional settings, Sino-Japanese する-verbs are everywhere. 確認かくにんする (to confirm), 対応たいおうする (to handle/respond), and 連絡れんらくする (to contact) appear in every workplace email and meeting. Learning the する pattern isn't a textbook exercise — it's what you'll need the first time you read a message from a Japanese colleague.

The phrase にする also reflects something culturally specific: making decisions without putting pressure on others. At a café, コーヒーにします signals a quiet, decisive choice — polite and clear. It lands more naturally than コーヒーを飲のみます (I will drink coffee) when someone is waiting for your order.

Finally, onomatopoeic + する expressions show how Japanese packs a rich world of sensation into everyday speech. ふわふわする (feeling light or dreamy), ぺこぺこする (starving), わくわくする (thrilled with anticipation). These aren't childish expressions — they appear in novels, news commentary, and adult conversation all the time.

Related Grammar Points

• たことがある — Have Done Before (Grammar N5)
• ながら — While Doing Two Things at Once (Grammar N5)
• てください — Please Do (Grammar N5)
• ましょう — Let's Do Something Together (Volitional Polite) (Grammar N5)
• ている — Progressive and Resultant State (Grammar N5)
• つもり — Intend To, Plan To (Grammar N5)

JLPT Tips

On the JLPT N5, する appears in virtually every section — vocabulary, grammar, and reading comprehension. Examiners test whether you can correctly identify the polite forms (します、しません、しました、しませんでした) and apply them in context. Have all four forms memorized cold before test day.

A common N5 question type involves selecting the correct form of する to complete a sentence. Watch tense markers closely: 昨日きのう (yesterday → past), 明日あした (tomorrow → non-past), 今いま (now → present/ongoing). These time words are usually your clearest clue when choosing between しました and します.

Vocabulary sections also test する-compound verbs. 勉強べんきょうする, 練習れんしゅうする, 電話でんわする — these appear as full vocabulary items, and you are expected to recognize and use them. Compiling a list of 20–30 common N5 する-verbs is one of the most efficient things you can do before the exam.

In reading passages, watch for して connecting two clauses. For example: 宿題しゅくだいをして、寝ねました (I did my homework and went to sleep). Recognizing that して links sequential actions helps you parse longer sentences that might otherwise look overwhelming.

Study tip: Each time you learn a new Japanese noun — especially two-kanji compound words of Chinese origin — ask yourself: Can I add する to this? More often than not, the answer is yes, and you've just learned a new verb for free.