Conversational Japanese Quiz: Expressing Ability Desire And Obligation
10 questions · exam conditions
0:00
Expressing Ability Desire And ObligationQuestion 1 of 10

A doctor tells a patient: 'You should not eat sweet things.' Which Japanese sentence most accurately conveys this recommendation?

甘いものを食べることができません。— This states the patient is physically unable to eat sweets, not that they are advised against it.
甘いものを食べたくないです。— This expresses the patient's personal desire not to eat sweets, not the doctor's recommendation.
甘いものを食べなければなりません。— This states the patient must eat sweets, which is the opposite of the intended meaning.
甘いものを食べないほうがいいです。— This uses 〜ないほうがいいです to express that it is better not to do something, correctly conveying the doctor's advice.
← Back to quizzes

Conversational Japanese Quiz

Conversational Japanese Quiz: Expressing Ability Desire And Obligation

Practice Expressing Ability Desire And Obligation in Conversational Japanese with focused quiz questions that help you check what you know, review explanations, and build confidence with test-style prompts.

What this quiz covers

This quiz focuses on Expressing Ability Desire And Obligation, giving you a quick way to practice the rules, question types, and explanations that matter most for Conversational Japanese.

How to use this quiz

Try each quiz question before looking at the correct answer. Use the explanations to review missed ideas, then come back to similar questions until the pattern feels familiar.

All questions

Question 1

A doctor tells a patient: 'You should not eat sweet things.' Which Japanese sentence most accurately conveys this recommendation?

  1. 甘いものを食べることができません。— This states the patient is physically unable to eat sweets, not that they are advised against it.
  2. 甘いものを食べたくないです。— This expresses the patient's personal desire not to eat sweets, not the doctor's recommendation.
  3. 甘いものを食べなければなりません。— This states the patient must eat sweets, which is the opposite of the intended meaning.
  4. 甘いものを食べないほうがいいです。— This uses 〜ないほうがいいです to express that it is better not to do something, correctly conveying the doctor's advice. (correct answer)
Explanation: When a Japanese question asks you to convey advice or a recommendation — especially from an authority figure like a doctor — you need to identify which grammar structure expresses "it would be better (not) to do something" rather than ability, desire, or obligation. The key structure here is 〜ないほうがいいです, which combines the negative verb form with ほうがいい ("it is better") to gently but clearly advise against an action. In D, 甘いものを食べないほうがいいです literally means "it is better not to eat sweet things," which perfectly mirrors a doctor's recommendation to avoid sweets. This is the standard, natural way to give or report advice in Japanese. The distractors each test a different grammar point. A uses 〜ことができません, which expresses a lack of ability or permission — it says the patient cannot eat sweets (as if physically incapable), not that they are advised against it. B uses 〜たくないです, the 〜たい form expressing personal desire — it reflects the patient's own feelings ("I don't want to eat sweets"), not any external advice from the doctor. C uses 〜なければなりません, the structure for obligation or necessity ("must/have to") — but crucially, it lacks the negative, so it actually means the patient must eat sweets, the complete opposite of the intended meaning. A useful tip: memorize the contrast between ほうがいいです (positive recommendation: "you should do X") and ないほうがいいです (negative recommendation: "you should not do X"). These appear frequently in medical and daily-advice scenarios on Japanese exams.

Question 2

田中さんは毎朝早く起きなければなりません。でも、今日は日曜日なので、早く起きなくてもいいです。

Which sentence correctly summarizes what the passage tells us about 田中さん on Sundays?

  1. 田中さんは日曜日に早く起きなければなりません。— She must wake up early on Sundays because it is her daily obligation.
  2. 田中さんは日曜日に早く起きたいです。— She wants to wake up early on Sundays because she enjoys mornings.
  3. 田中さんは日曜日に早く起きなくてもいいです。— She does not have to wake up early on Sundays, so the daily obligation does not apply. (correct answer)
  4. 田中さんは日曜日に早く起きることができません。— She is unable to wake up early on Sundays due to a physical limitation.
Explanation: This question tests your ability to distinguish between Japanese grammar patterns that express obligation, desire, ability, and permission not to do something — all of which look similar but carry very different meanings. The key phrase in the passage is 「早く起きなくてもいいです」. This construction breaks down as: verb in negative て-form (起きなくて) + もいいです, which means "it is okay not to do ~" or "you don't have to ~." The passage sets up a contrast: normally 田中さん must wake up early (なければなりません), but because today is Sunday, that obligation is lifted. This makes C the correct answer — it accurately captures that her daily obligation does not apply on Sundays. A is wrong because it uses 「なければなりません」, which expresses strong obligation ("must"). The passage explicitly says the opposite — Sunday is the exception from that obligation, not an extension of it. B introduces 「起きたいです」, meaning "wants to wake up early." Nothing in the passage mentions her feelings or desires about mornings — this information is completely invented and not supported by the text. D uses 「起きることができません」, meaning "is unable to wake up early," which describes a physical inability. The passage says nothing about capability; it is purely about whether an obligation exists. A useful pattern to remember: 「〜なければなりません」 = must do / obligation, while 「〜なくてもいいです」 = don't have to / permission to skip. Mixing these two up is one of the most common errors at this level, so practice recognizing both patterns on sight.

Question 3

A student wants to say: 'My younger sister can speak three languages.' Which Japanese sentence correctly expresses this ability?

  1. 妹は三つの言語を話したいです。— This uses 〜たいです to indicate personal desire rather than a demonstrated skill.
  2. 妹は三つの言語を話さなければなりません。— This uses 〜なければなりません to indicate a requirement, not an ability.
  3. 妹は三つの言語が話せます。— This uses the potential form 話せます, correctly expressing that she has the ability to speak three languages. (correct answer)
  4. 妹は三つの言語を話すべきです。— This uses 〜べきです to indicate what she ought to do, not what she is capable of doing.
Explanation: When a Japanese question asks you to express ability — what someone can do — your first instinct should be to reach for the potential form of a verb. In Japanese, potential forms convey demonstrated skill or capability, and recognizing them is essential for accuracy on grammar questions like this one. The verb 話す (to speak) becomes 話せる in its potential form, and 話せます is the polite present tense. Notice also that the particle shifts from を to が — this is a key grammatical feature of potential constructions in Japanese. So 妹は三つの言語が話せます literally means "As for my younger sister, she is able to speak three languages," which perfectly captures the intended meaning. That makes C the correct answer. Each wrong answer uses a grammatical structure that looks like it could work but expresses a completely different meaning. A uses 〜たいです, which expresses the speaker's desire ("wants to speak") — not ability. B uses 〜なければなりません, meaning "must" or "has to" — this is obligation, not capability. D uses 〜べきです, meaning "should" or "ought to" — again, a moral or logical expectation, not a skill. A helpful study tip: memorize these four structures as a set — たいです (want), なければなりません (must), べきです (should), and the potential form (can). Exam questions frequently swap them to test whether you truly understand the nuance of each. When you see "can" or "ability," go straight to the potential form and check for the particle が.

Question 4

ケンさんは来週のパーティーに行きたいです。でも、来週は試験があるので、たくさん勉強しなければなりません。

Based on the passage, which statement BEST describes ケン's situation using the correct grammar forms?

  1. ケンさんはパーティーに行けますが、勉強したいです。— This reverses the relationship: ability is stated for the party and desire is stated for studying.
  2. ケンさんはパーティーに行きたいですが、勉強しなければなりません。— This captures both his desire to go to the party and his obligation to study for the exam. (correct answer)
  3. ケンさんはパーティーに行きたくないですが、勉強できます。— This incorrectly states he does not want to go and uses ability rather than obligation for studying.
  4. ケンさんはパーティーに行くべきですが、勉強しなくてもいいです。— This suggests he ought to go to the party and does not need to study, contradicting the passage.
Explanation: When reading a Japanese passage and choosing the best summary, you need to match each grammar form to the meaning it carries — desire (〜たい), obligation (〜なければなりません), ability (〜できる), and "don't have to" (〜なくてもいい). The passage tells us two things: Ken wants to go to the party (行きたい) and must study because of an exam (勉強しなければなりません). Your job is to find the answer that preserves both of those meanings accurately. Choice B does exactly that. 「行きたいですが、勉強しなければなりません」 keeps his desire to attend the party intact and correctly reflects the obligation to study — making it the best summary of the passage. Choice A reverses the grammar entirely: it says Ken can go (行けます, ability) and wants to study (勉強したい, desire) — the opposite of what the passage states. Choice C compounds two errors: it says Ken does not want to go (行きたくない) and uses ability (勉強できます) instead of obligation, contradicting the passage on both points. Choice D introduces 行くべき ("should go"), which implies a moral duty to attend, and 勉強しなくてもいい ("doesn't need to study"), which directly contradicts the passage's whole point about the exam pressure. A useful habit: whenever a question tests grammar forms, list the key verbs in the passage and label each one's form before reading the choices. That way, you're matching meanings systematically rather than relying on what "sounds right."

Question 5

アンさんは日本語で手紙を書くことができます。彼女は日本の友達に手紙を書きたいですが、今週は仕事がとても忙しいので、書く時間がありません。

Which statement about アン is TRUE according to the passage, and which grammar form supports it?

  1. アンさんには日本語で手紙を書く能力がありません。This is supported by 書くことができます, which actually asserts her ability, so this statement misreads the passage.
  2. アンさんは日本語で手紙を書く能力がありますが、今週は書きません。This is supported by 書くことができます (she can write) and the implied result that she will not write this week due to her busy schedule. (correct answer)
  3. アンさんは手紙を書く義務がありますが、書きたくありません。This incorrectly introduces obligation; the passage uses desire (書きたい), not obligation (〜なければならない), and she does want to write.
  4. アンさんは仕事が忙しいので、日本語が話せません。This introduces speaking ability (話せません) and a causal link to work that is not stated in the passage; the passage discusses writing, not speaking.
Explanation: When reading a Japanese passage and answering comprehension questions, your first job is to identify exactly what grammar forms are used and what they actually express — ability, desire, obligation, or something else entirely. The passage tells you two key things about アン: she can write letters in Japanese (書くことができます, expressing ability), and she wants to write to her Japanese friend (書きたいです, expressing desire). However, because work is very busy this week (今週は仕事がとても忙しいので), she has no time to write (書く時間がありません). Putting this together, B is correct — アン has the ability to write, but she will not be writing this week due to circumstances beyond her desire. As for the wrong answers: A directly contradicts the passage by claiming アン lacks writing ability, when 書くことができます clearly asserts she has that ability. C incorrectly introduces the idea of obligation (義務), suggesting she must write but doesn't want to — this misreads both the grammar (no 〜なければならない appears) and her feelings (she actually wants to write). D shifts the topic entirely to speaking ability (話せません) and falsely links her busy schedule to her Japanese language skills — the passage never mentions speaking at all. A useful strategy: before evaluating answer choices, mentally note the grammar structures in the passage — できます (ability), たい (desire), ので (reason/cause) — and treat them as a checklist. Any answer choice that swaps one structure for another (desire → obligation, writing → speaking) is almost certainly a trap.

Question 6

Which of the following sentences contains a grammatical error in expressing desire?

  1. 私は新しいスマートフォンを買いたいです。— Correct: 〜たいです is properly attached to the verb stem 買い, expressing desire to buy.
  2. 彼女は日本に行きたいと思っています。— Correct: 〜たいと思っています is a natural and grammatical way to express an ongoing wish or desire.
  3. 弟は野菜を食べたくないです。— Correct: The negative desire form 〜たくないです is properly attached to the verb stem 食べ.
  4. 先生はもっと休みをしたいです。— Incorrect: を+し+たいです is unnatural here. The correct form is 休みたいです (attaching 〜たい directly to the verb 休む) or 休憩したいです. (correct answer)
Explanation: When expressing desire in Japanese, the key structure to master is 〜たい, which attaches directly to the verb stem (the ます-form minus ます). This question tests whether you can spot an unnatural or incorrect application of that pattern. The problematic sentence is D: 「先生はもっと休みをしたいです。」 The phrase 休みをする treats 休み as a noun object of する, but this construction is unnatural and redundant. Japanese does not typically say 休みをする to mean "to rest." The natural forms are either 休みたいです (attaching 〜たい directly to the stem of 休む) or 休憩したいです (using the proper noun+する compound 休憩する). The error in D is forcing a clunky noun+をする structure where a simple verb or a proper suru-verb should be used instead. Options A, B, and C are all grammatically sound. In A, 買いたいです correctly attaches 〜たいです to the verb stem 買い. In B, 〜たいと思っています is the natural way to express an ongoing or reported desire, especially when talking about someone else's wishes indirectly. In C, the negative desire form 〜たくないです is correctly formed from 食べ + たくないです — remember that たい conjugates like an い-adjective, so its negative is たくない, not たいじゃない. Study tip: Whenever you see desire expressions, check two things: (1) Is 〜たい attached to a verb stem, not a noun? (2) If a suru-verb is involved, is it a real compound like 勉強する, or an awkward noun+をする construction? That distinction catches many errors.

Question 7

マリアさんは子どもの頃、ピアノが弾けませんでした。でも、今は毎日練習しているので、上手に弾けます。

Which sentence correctly describes the CHANGE in Maria's ability as conveyed by the passage?

  1. マリアさんはずっとピアノが弾けます。— This implies she has always been able to play piano, ignoring her past inability mentioned in the passage.
  2. マリアさんは子どもの頃からピアノを弾きたかったです。— This focuses on past desire, but the passage discusses ability (弾けます/弾けませんでした), not desire.
  3. マリアさんは昔はピアノが弾けませんでしたが、今は弾けます。— This correctly uses the potential form in both past negative and present positive to show the development of her ability. (correct answer)
  4. マリアさんは子どもの頃ピアノを弾かなければなりませんでしたが、今は弾かなくてもいいです。— This incorrectly frames her piano playing as an obligation rather than a skill she developed.
Explanation: When a passage describes how someone's ability changed over time, your job is to find the sentence that accurately captures both the past state and the present state using the correct grammatical forms — especially the potential form (〜できる/弾ける) versus obligation or desire forms. The passage tells us two things: Maria could not play piano as a child (弾けませんでした), and she can play now (弾けます). Choice C — マリアさんは昔はピアノが弾けませんでしたが、今は弾けます — nails this perfectly. It uses the potential form in both clauses: past negative (弾けませんでした) and present positive (弾けます), with the contrastive particle が linking them to show a clear development of skill over time. Choice A fails because ずっと ("all along / always") implies she has been able to play piano continuously, which directly contradicts the passage's statement that she couldn't as a child. Choice B shifts the focus entirely to desire (〜たかった = "wanted to"), but the passage never mentions what Maria wanted — it only discusses her ability. Don't confuse 弾きたい (want to play) with 弾ける (can play). Choice D introduces obligation grammar: 弾かなければなりませんでした (had to play) and 弾かなくてもいいです (doesn't have to play). This completely reframes her piano journey as a matter of duty, not skill development. As a study tip: whenever you see 〜できる/〜える potential forms in a passage, watch for answer choices that quietly swap in desire (〜たい) or obligation (〜なければならない) grammar — this is a classic trap designed to test whether you can distinguish ability from want and must.

Question 8

A student writes: 「医者に言われたので、毎朝薬を 。」 Which option correctly fills the blank to mean 'Because the doctor told me (I must take it), I drink medicine every morning'?

  1. 飲みたいです — This uses desire (〜たい), implying the speaker personally wants to take medicine rather than doing so out of medical instruction.
  2. 飲めません — This uses the negative potential form, implying the speaker cannot drink medicine, which contradicts the action described in the sentence.
  3. 飲まなければなりません — This correctly uses 〜なければなりません (must/have to), expressing that the obligation to take medicine is the reason for the morning routine. (correct answer)
  4. 飲むべきではありません — This uses 〜べきではない (should not), which is the opposite of the intended obligation and contradicts the action described.
Explanation: When a sentence explains that someone was told to do something by an authority figure (like a doctor), you should immediately look for an obligation expression in the blank — something that conveys "must" or "have to," not desire or ability. The grammar pattern 〜なければなりません means "must do" or "have to do" and is built from the negative conditional form of a verb plus なりません. Here, 飲まなければなりません ("must drink/take") fits perfectly because the speaker is explaining that the doctor's instruction creates an obligation — taking medicine every morning isn't optional or desired, it's required. This makes option C the correct answer. Looking at the distractors: A (飲みたいです) uses the 〜たい form, which expresses personal desire. The sentence isn't saying the speaker wants to take medicine — they're doing it because they have to. This is a common trap because wanting and being obligated can feel similar in English. B (飲めません) uses the negative potential form, meaning "cannot drink," which directly contradicts the sentence's meaning — the speaker is taking medicine, not failing to. D (飲むべきではありません) uses 〜べきではない, meaning "should not do," which is the complete opposite of the obligation described. This one is tempting if you confuse べきではない with べきです, so be careful with negation. A useful study tip: when you see ので (because) connecting a reason involving an authority or rule, scan your answer choices for obligation patterns like 〜なければなりません or 〜なくてはいけません, and eliminate desire (〜たい) and ability (〜られる/〜える) forms first.

Question 9

Which pair of sentences is grammatically correct AND accurately contrasts desire with obligation?

  1. 私はケーキを食べたいです。／私はケーキを食べなければなりません。— Both sentences are grammatically correct; the first expresses desire and the second expresses obligation, forming a true contrast. (correct answer)
  2. 私はケーキが食べられたいです。／私はケーキを食べなければなりません。— The first sentence incorrectly combines the potential form 食べられ with 〜たい, which is ungrammatical in standard Japanese.
  3. 私はケーキを食べたいです。／私はケーキが食べなければなりません。— The second sentence uses が instead of を/は with 〜なければなりません, creating an unnatural and grammatically awkward construction.
  4. 私はケーキを食べたくてです。／私はケーキを食べないといけないです。— The first sentence incorrectly uses 〜たくて in isolation as a final predicate, which is ungrammatical without a following clause.
Explanation: When expressing desire in Japanese, you use 〜たい attached directly to the verb stem (食べ + たい → 食べたい). For obligation, the standard pattern is 〜なければなりません attached to the negative stem. Questions like this test whether you can identify both the grammatical correctness of each pattern and whether the pair genuinely contrasts desire versus obligation. Answer A is correct on both counts. 食べたいです follows the proper formation — verb stem + たい + です — and clearly expresses "I want to eat cake." The second sentence, 食べなければなりません, correctly uses を as the object marker with this obligation structure, meaning "I must eat cake." Together they form a clean, accurate contrast. Answer B fails because it combines the potential form 食べられ with 〜たい, producing 食べられたい. In standard Japanese, you attach 〜たい directly to the plain verb stem, not to the potential form. If you want to say "I want to be able to eat," you'd restructure the sentence entirely rather than stacking these forms. Answer C contains a subtle but real error: using が as the object marker with 〜なければなりません. While が can appear with certain adjective-based desire expressions (like 〜たい), it is unnatural and awkward with 〜なければなりません, which requires を or は. Answer D uses 〜たくて as a sentence-final predicate, but 〜たくて is a conjunctive (te-form of たい) meant to connect clauses — it cannot stand alone as a complete predicate. Study tip: Always attach 〜たい directly to the verb stem, and remember that 〜なければなりません pairs naturally with を, not が.

Question 10

A student is trying to say: 'You don't have to come to the meeting tomorrow.' Which sentence correctly expresses this idea in Japanese?

  1. 明日の会議に来なくてもいいです。— This uses 〜なくてもいいです to express that coming is not necessary or required, correctly conveying 'you don't have to come.' (correct answer)
  2. 明日の会議に来てはいけません。— This uses 〜てはいけません to express prohibition (you must not come), which is stronger and different from simply not being required to come.
  3. 明日の会議に来なければなりません。— This expresses the obligation to come (must come), which is the opposite of the intended meaning.
  4. 明日の会議に来ることができません。— This uses the negative potential form to say 'you cannot come,' expressing inability rather than the absence of an obligation.
Explanation: When expressing degrees of obligation in Japanese, it helps to recognize that the language has distinct grammar patterns for "must," "must not," "cannot," and "don't have to" — and mixing them up is one of the most common mistakes on Japanese exams. The phrase you need here is 〜なくてもいいです, which literally means "even without doing [X], it's fine." It removes an obligation rather than creating one. Answer A, 明日の会議に来なくてもいいです, uses exactly this pattern with 来る (to come) in its negative te-form (来なくて), making it the correct way to say "you don't have to come to tomorrow's meeting." Each wrong answer represents a different, specific grammar pattern. Answer B, 来てはいけません, uses 〜てはいけません, which expresses prohibition — "you must not come." This is stronger and almost the opposite in nuance; it forbids attendance rather than making it optional. Answer C, 来なければなりません, uses 〜なければなりません, meaning "must come" or "have to come" — this expresses obligation to attend, which is the exact opposite of what the student wants to say. Answer D, 来ることができません, uses the negative potential form できません, meaning "you are unable to come" — this describes a lack of ability, not a lack of requirement. A useful memory trick: think of Japanese obligation patterns as a spectrum — 〜なければなりません (must do) → 〜てはいけません (must not do) → 〜なくてもいいです (don't have to do). Knowing where each pattern sits on that spectrum will help you avoid swapping them under pressure.