N5 · Unit 5
Lesson 19Please do not, must, and do not have to
Make a negative request, state an obligatory action, and say that an action is not required.
What you learn
Make a negative request, state an obligatory action, and say that an action is not required.
Learning points
- Negative verb forms
- Negative requests and obligation
- No obligation
Why this lesson comes now
This lesson connects what you can already say to a new way of expressing it. Hear the key sentences, understand the structure, then use it in a real situation.
Your next step
Listen to the key sentences, understand the pattern, finish the examples and vocabulary, then continue to the next lesson.
Open the interactive lessonCore pattern
動詞ないで ください ・ 動詞なければ なりません ・ 動詞なくても いいですBeginner explanation
Use 〜ないでください to ask someone not to do something. Use 〜なければなりません for an obligation and 〜なくてもいいです when an action is not required. All three patterns build from the negative ない-form.
Understand these sentences first
- ここで タバコを 吸わないで ください。koko de tabako o suwanaide kudasai
Please do not smoke here.
- 明日 早く 起きなければ なりません。ashita hayaku okinakereba narimasen
I must get up early tomorrow.
- この 薬を 飲まなければ なりません。kono kusuri o nomanakereba narimasen
I must take this medicine.
- 今日は 宿題を しなくても いいです。kyō wa shukudai o shinakute mo ii desu
You do not have to do homework today.
Core vocabulary
- 吸いますすいますsmoke; inhale
- 薬くすりmedicine
- 飲みますのみますdrink; take medicine
- 宿題しゅくだいhomework
- 返しますかえしますreturn
- 忘れますわすれますforget
- 入りますはいりますenter
- 早くはやくearly; quickly
Grammar, one point at a time
The verb nai-form changes by class
Vます → VないGroup 1 moves the final stem sound to the a-row and adds ない. Verbs ending in う, such as 買います, use わ: 買わない. Group 2 removes ます and adds ない. 来ます becomes 来ない and します becomes しない.
Examples
- 書きます → 書かないwrite → nai-form
- 読みます → 読まないread → nai-form
- 買います → 買わないbuy → nai-form
- 食べます → 食べないeat → nai-form
Vないでください means please do not
Vないで くださいPut the verb in the nai-form and add でください. It is a polite negative request but remains direct; give a reason or use a softer expression when needed.
Examples
- 部屋の かぎを 忘れないでください。Please do not forget the room key.
- この 品物に 触らないでください。Please do not touch this item.
- 無理を しないでください。Please do not overdo it.
Vなければなりません means must do
Vなければ なりません／Vないと いけませんReplace ない with なければなりません. Conversation often uses ないといけません, or shortened ないと when context is clear. It states necessity but does not itself identify who imposed it.
Examples
- 今日は 早く 帰らなければ なりません。I must go home early today.
- 書類を すぐ 送らないと いけません。I have to send the documents immediately.
- もう 行かないと。I have to go now.
Vなくてもいいです means it is not necessary
Vなくても いいですReplace ない with なくてもいいです. It removes an obligation and does not prohibit the action. Whether it is truly unnecessary should be confirmed with the relevant authority or rule.
Examples
- 明日は 残業しなくても いいです。You do not have to work overtime tomorrow.
- 靴を 脱がなくても いいですか。May I leave my shoes on?
New identifying information takes が in which or who answers
new information が known category ですWhen answering どの方が山田先生ですか or 吉田課長はいますか, identify the new person with が: あの方が山田先生です or わたしが吉田です. A question word used as subject also takes が, not は.
Examples
- どの 人が 田中さんですか。— あの 人が 田中さんです。Which person is Tanaka? — That person is Tanaka.
- だれが いますか。Who is there?
- 何が 好きですか。What do you like?
Expressions and situations
なければなりません is more formal; ないといけません is conversational
The former is common in formal speech and writing, while the latter is common in conversation. Shortened ないと requires clear context.
- 明日までに 提出しなければ なりません。It must be submitted by tomorrow.
- もう 帰らないと。I have to go home.
Skill levels use 初級, 中級, and 上級; learners may be 初心者 or 上級者
高級 mainly describes high-grade goods, services, or quality and does not name a person's skill level. An advanced class is 上級クラス.
- 初心者コースに 入ります。I will enter the beginner course.
- 上級クラスで 勉強しています。I study in an advanced class.
Quantity + も + affirmative emphasizes a surprisingly large amount
Use 何度も転びました or 水を5杯も飲みました. The speaker presents the quantity as large; it is not an objective fixed threshold.
- 何度も 練習しました。I practised many times.
だいぶ marks a substantial degree or change
It commonly pairs with change expressions such as よくなりました or 上手になりました. It is stronger than 少し but gives no exact percentage.
- だいぶ 上手に なりました。You have improved considerably.
大丈夫です can mean fine, recovered, or I can manage
Context determines the meaning. Because it can also be read as refusal or permission, add the full fact in safety or medical situations.
- もう 大丈夫です。I am all right now.
- 大丈夫です。上級コースには 行きません。It is fine. I will not enter the advanced course.
残業 means work beyond scheduled or statutory hours
Whether overtime is required, whether an Article 36 agreement is needed, limits, and premium pay depend on law, industry exceptions, contract, and workplace rules. MHLW states that the general limits are in principle 45 hours per month and 360 hours per year, with annual, monthly, and multi-month limits even under special clauses. For a specific workplace issue, check current official rules or seek professional advice.
- 今日は 残業しなければ なりませんか。Do I have to work overtime today?
- 明日は 残業しなくても いいです。You do not have to work overtime tomorrow.
Slope level and opening status must follow the day's resort signs
初心者コース and 上級者コース are language labels and do not guarantee identical difficulty across resorts. Beginners should consider lessons, suitable equipment, and conditions and must not enter closed or beyond-skill areas.
- 上級者コースに 入らないでください。Please do not enter the advanced course.
What you should be able to do
- Convert Group 1, 2, and 3 verbs to the nai-form, especially う→わ.
- Use ないでください for negative requests about forgetting, touching, entering, and discarding.
- Switch among formal なければなりません, conversational ないといけません, and shortened ないと.
- Distinguish lack of necessity なくてもいい from negative request ないでください.
- Ask with question word + が and answer an identity with new information + が.
- Complete an original ski-resort task: identify level, understand rules, express obligations and no necessity, and decline a route beyond your ability.
Culture and real use
Rules before assumptions: overtime limits and slope safety
MHLW states that statutory working hours in Japan are in principle eight hours per day and 40 per week. Overtime beyond them generally requires an Article 36 agreement; the general limits are 45 hours per month and 360 per year, while special clauses remain subject to annual, single-month, and multi-month limits and some sector-specific rules. For skiing and snowboarding, JNTO recommends lessons for first-timers, warm waterproof clothing, suitable gear, and checking rentals, instruction, and resort rules in advance. Colours and difficulty labels vary by resort. Backcountry outside patrolled areas carries avalanche, tree-well, and rescue risks and requires specialist skills, equipment, current conditions, and experienced guides.
- 初心者コースは どこですか。Where is the beginner course?
- この コースに 入っても いいですか。May I enter this course?
- 今日は 残業しなければ なりませんか。Do I have to work overtime today?