ないでください — Please Don't

Meaning & Usage

ないでください (naide kudasai) is the standard grammar pattern beginners need for making a polite negative request — asking someone not to do something. The pattern appears constantly in everyday Japanese life, from signs in public places to instructions given by teachers, doctors, and service staff.

The English equivalent is simply "Please don't ~" or "Please refrain from ~ing." For example, if you want to say "Please don't smoke here," you would say ここでタバコを吸すわないでください (koko de tabako wo suwanaide kudasai). The structure is straightforward once you learn how to form the ない (nai) form of verbs.

Regarding register, ないでください sits in the polite neutral range. Use it wherever you would use です/ます speech: at a store, at school, at work, or with people you do not know well. Respectful without being stiff, it works comfortably with strangers, colleagues, and authority figures alike.

Worth distinguishing from the casual ないで (naide) used alone, or the blunt negative imperative な (na) attached to the dictionary form — both carry a more direct, informal, or even harsh tone, reserved for close friends or urgent emergencies. ないでください keeps the interaction polite and socially smooth, which matters in Japanese communication.

The でください part comes from the same source as the positive request てください (te kudasai), meaning "please do ~." Attaching でください to the ない-form flips the request from positive to negative. Once you understand both forms, the symmetry makes the grammar intuitive and gives you a reliable tool for setting boundaries and giving instructions across a wide range of real-world situations.

Structure & Formation

The formation of ないでください follows a consistent two-step rule: first, conjugate the verb into its ない-form (plain negative form), then attach でください directly to the end.

Core formula: Verb (ない-form) + でください

The key step is knowing how to form the ない-form for each verb group. Japanese verbs are divided into three conjugation groups, and each follows its own rule for forming the negative.

Pay special attention to u-verbs ending in う (u): the negative stem changes to わ (wa), not あ (a). So 使つかう (tsukau) → 使つかわない (tsukawanai), and 歌うたう (utau) → 歌うたわない (utawanai). This is one of the most frequently tested points at the N5 level.

Example Sentences

Everyday Requests

Classroom and School Settings

Public Places and Signs

Expressing Care and Concern

Daily Life Instructions

Common Mistakes

Mistake 1: Omitting で — writing ないください instead of ないでください

❌ ここでタバコを吸すわないください。

✅ ここでタバコを吸すわないでください。

Many beginners forget the で particle that sits between ない and ください. This で is not optional — without it, the sentence is ungrammatical. The complete, unbreakable sequence is always ない + で + ください. A useful way to remember: でください is a fixed phrase that always comes as a unit.

Mistake 2: Using the dictionary form instead of the ない-form

❌ タバコを吸すうないでください。

✅ タバコを吸すわないでください。

The verb must be fully conjugated into its ない-form before adding でください. Placing the dictionary form directly before ないでください produces an ungrammatical sentence. Always conjugate first: 吸すう → 吸すわ + ない → 吸すわないでください. Skipping this step is the single most common structural error.

Mistake 3: Using the polite ません form before でください

❌ タバコを吸すいませんでください。

✅ タバコを吸すわないでください。

Some learners attach でください to the polite negative ません-form, reasoning that it sounds more polite. This is incorrect Japanese. The でください construction always requires the plain ない-form as its base. The politeness in ないでください comes from ください itself, not from the verb form before it.

Mistake 4: Using な instead of ないでください in polite or formal settings

❌ ここで食たべるな。(Too blunt for polite situations)

✅ ここで食たべないでください。

The short imperative な attached to the dictionary form is extremely direct and can come across as rude or aggressive, especially toward strangers, customers, or superiors. Occasionally used between very close friends or in urgent situations involving immediate danger, it is otherwise inappropriate. In all polite contexts, ないでください is the correct and socially appropriate choice.

Mistake 5: Forgetting the special う → わ change in U-verbs ending in う

❌ 携帯けいたいを使つかあないでください。

✅ 携帯けいたいを使つかわないでください。

Verbs ending in the hiragana う (u) change to わ (wa) — not to あ (a) — when forming the negative. Therefore 使つかう (tsukau) → 使つかわない (tsukawanai), 歌うたう (utau) → 歌うたわない (utawanai), and 言いう (iu) → 言いわない (iwanai). This well-known exception to the standard u-verb pattern is specifically tested on the JLPT N5 exam.

Cultural Notes

Walk through any Japanese public space and you will encounter ないでください on signs. Museums, temples, shrines, trains, hospitals, and restaurants all use this form to communicate rules and requests to visitors. A typical museum, for example, will display 展示物てんじぶつに触さわらないでください (Please don't touch the exhibits) and 写真しゃしんを撮とらないでください (Please don't take photographs) throughout its halls.

Japanese culture places a high value on maintaining social harmony (和, wa) and avoiding direct confrontation. ないでください expresses a clear boundary in a manner that remains considerate and non-aggressive. Even when someone is doing something quite inconvenient or disruptive, the form allows the speaker to address it while preserving the dignity of both parties.

Service industries — hotels, clinics, schools, and department stores — rely on ないでください as part of standard professional communication. A nurse might say 無理むりをしないでください (Please don't push yourself too hard); a hotel front desk employee might say 部屋へやの外そとで食たべないでください (Please don't eat outside the room). Both examples show how the form balances authority with respect.

In more formal written contexts — official notices, government pamphlets, safety instructions — you may sometimes see the slightly more indirect ないようにしてください (nai you ni shite kudasai), meaning "please make sure not to ~." For everyday spoken and general written use, however, ないでください remains the standard form you will hear and need most.

Related Grammar Points

• てください — Please Do (Grammar N5)
• ましょう — Let's Do Something Together (Volitional Polite) (Grammar N5)
• てもいい — May, It's Ok To (Grammar N5)
• ます — Polite Verb Ending (Grammar N5)
• と思う — I Think That (Grammar N5)
• ほうがいい — Should, Had Better (Grammar N5)

JLPT Tips

ないでください is a core N5 grammar point and highly likely to appear in some form on the JLPT N5 examination. You should be able to recognize it instantly, produce it correctly, and distinguish it from closely related forms.

Sentence completion questions will ask you to select the correct form of a verb to fill a blank before でください. You need to supply the ない-form accurately. Drill verb conjugation across all three groups — Group 1, Group 2, and the two irregular verbs する and くる — until the transformations are completely automatic.

Grammar selection questions may ask you to choose between ないでください, てください, なくてもいいです, and similar patterns. Focus on meaning distinctions: ないでください = polite negative request (please don't do), てください = polite positive request (please do), なくてもいいです = permission not to do (you don't have to do). These three are frequently contrasted in N5 exam questions.

Reading comprehension passages may include notices, signs, or short texts using ないでください. In those contexts, identify it as a polite prohibition or restriction — something the reader is being asked not to do — and choose your answer accordingly.

One final test-day reminder: always check the verb conjugation carefully before selecting your answer. The irregular verbs する → しない and 来くる → 来こない, and the u-verb う → わ exception (e.g., 使つかう → 使つかわない), are classic traps in N5 grammar questions precisely because they deviate from the regular pattern. Remember too that ないでください is the polite neutral form appropriate for most contexts — knowing when not to use the casual variants な and ないで is itself tested knowledge at this level.