“kanarazu・kanarazu shimo 〜nai”: Definitely vs Not Necessarily [JLPT N3]
By Nihongo to Japan · Updated July 3, 2026
“Kanarazu kite kudasai” vs “takai mono ga kanarazu shimo yoi to wa kagiranai”
“kanarazu・kanarazu shimo 〜nai”: Definitely 〜 vs Not Necessarily 〜
These two adverbs are easily confused. 「必ず」＋ affirmative = “certainly, without fail, be sure to,” marking objective inevitability or a strong request. 「必ずしも」＋ negative = “not necessarily,” a partial negation. One character apart, nearly opposite: 「必ず来てください」 (please be sure to come) vs 「高いものが必ずしも良いとは限らない」 (expensive things aren't necessarily good).
🧠 Core difference: 必ず = 100%, 必ずしも = “not all of it”
必ず is an absolute 100% — no exceptions, it will happen, you must do it. 必ずしも instead discounts the idea “all/always 〜”: not a total denial, but “not every time, not always.” That's why 必ずしも almost always appears with a negative (〜ない／〜とは限らない); without one it doesn't work.
📌 How to Connect
| Expression | Pattern | Example |
|---|---|---|
| 必ず | 必ず ＋ affirmative (will / request / inevitability) | 必ず連絡します |
| 必ずしも | 必ずしも ＋ negative (often 〜とは限らない) | 必ずしも正しいとは限らない |
💬 Example Sentences
- 締め切りは必ず守ってください。(Please be sure to meet the deadline.) — strong request
- 春になれば必ず桜が咲く。(When spring comes, the cherry blossoms always bloom.) — objective inevitability
- お金持ちが必ずしも幸せだとは限らない。(The rich aren't necessarily happy.) — partial negation
- 高い物が必ずしも良いわけではない。(Expensive things aren't necessarily good.)
- 努力すれば必ず報われるとは、必ずしも言えない。(You can't necessarily say effort is always rewarded.) — both contrasted
🔄 Compare: 必ず vs きっと vs ぜひ vs 絶対
| Expression | Nuance | Example |
|---|---|---|
| 必ず | objective certainty / without fail | 必ず来てください |
| きっと | subjective guess (I bet…) | きっと来るよ |
| ぜひ | strong wish / invitation | ぜひ来てください |
| 絶対（に） | colloquial “absolutely” (emotional) | 絶対に行く |
⚠️ Common Mistakes
- 必ずしも ＋ affirmative: ✗ 必ずしも合格する → 必ずしも needs a negative (必ずしも合格するとは限らない).
- Reading 必ず＋negative as partial negation: 「必ず〜ない」 = “definitely not” (total), not “not necessarily”; use 「必ずしも〜ない」 for the latter.
- Guaranteeing a subjective guess with 必ず: for uncontrollable things (weather, others' feelings), きっと is more natural; 必ず sounds like a promise.
- Forgetting the closing negative after 必ずしも: the set pattern is 「必ずしも〜とは限らない／〜わけではない」.
💡 Nuance & When to Use
必ず suits rules, promises, and natural laws — formal, reliable, forceful. 必ずしも is an advanced tool for argumentative writing, conveying “it's not that absolute,” making a point feel measured and thoughtful. Both are common in speech, but 必ずしも leans written and slightly formal; used well, it makes your Japanese sound mature.
🎯 JLPT Exam Tips
- High-frequency N3: choosing between 必ず / 必ずしも — check the ending: affirmative → 必ず, negative (とは限らない) → 必ずしも.
- Memorize the pairing: 必ずしも ＋ とは限らない／わけではない.
- Distinction items often mix in きっと / ぜひ — only objective certainty is 必ず.
🖊️ Practice Quiz
Q1. 「締め切りは___守ってください。」(please be sure to meet the deadline)
(A) 必ず (B) 必ずしも (C) たぶん (D) もしかすると
Q2. 「お金持ちが___幸せとは限らない。」(the rich aren't necessarily happy)
(A) 必ずしも (B) 必ず (C) きっと (D) ぜひ
Q3. What does 「必ずしも〜ない」 express?
(A) Not necessarily (partial negation)
(B) Definitely (full affirmation)
(C) Absolutely not (full negation)
(D) Probably
Q4. What's the difference between 必ず and きっと?
(A) 必ず = objective certainty / be sure to; きっと = subjective guess
(B) Exactly the same
(C) 必ず = guess
(D) きっと = a request
Q5. Which usage is correct?
(A) 必ず連絡します。 (B) 必ず正しいとは限らない。
(C) 必ずしも合格する。 (D) 必ずしも行きます。
Answer Key
1. (A) 必ず ── be sure to (必ず ＋ affirmative).
2. (A) 必ずしも ── not necessarily happy (＋ negative).
3. (A) ── not necessarily / not always.
4. (A) ── 必ず is objective; きっと is a subjective guess.
5. (A) ── 必ず ＋ affirmative; (B) should be 必ずしも〜とは限らない; (C)(D) wrongly pair 必ずしも with affirmatives.