Japanese Negative Form: ない, ません, and なかった

All 4 Negative Forms at a Glance

Every Japanese verb has four negative forms. This featured table uses 食べる (eat, Group 2) and 書く (write, Group 1) as models.

The plain negative ending ない conjugates like an い-adjective: its past tense is formed by dropping い and adding かった → なかった.

Group 1 (Godan) Verbs — ない Form

Group 1 (godan) verbs end in one of eight consonant+う sounds. To form the negative, change the final う-row syllable to its あ-row equivalent and add ない. Exception: verbs ending in う itself change to わ (not あ) before ない.

Remember the う→わ rule: Any Group 1 verb that ends in bare う (like 買う、言う、会う) uses わ, not あ, before ない: 言わない (don't say), 会わない (don't meet).

Group 2 (Ichidan) Verbs — ない Form

Group 2 (ichidan) verbs always end in る preceded by an い-row or え-row vowel. The negative is the simplest in Japanese: drop the final る and add ない.

Watch out for look-alike Group 1 verbs: Some verbs end in る but are actually Group 1: 帰る (return) → 帰らない, 走る (run) → 走らない. When in doubt, check the vowel before る — if it's an あ、う、お-row sound, the verb is most likely Group 1.

Group 3 (Irregular) Verbs — する and くる

Only two irregular verbs exist in Japanese. Their negative stems must be memorised:

Compound verbs with する follow the same pattern: 勉強する (study) → 勉強しない / 勉強しません; 運動する (exercise) → 運動しない / 運動しません.

Negative Past Tense — なかった and ませんでした

The negative past is built from the ない form. Since ない acts as an い-adjective, making it past tense follows the い-adjective past rule: drop い, add かった.

Example sentences:

• 昨日、宿題をしなかった。 — I didn't do my homework yesterday. (plain)
• 先週、学校に来ませんでした。 — She didn't come to school last week. (polite)
• 朝ごはんを食べなかった。 — I didn't eat breakfast. (plain)
• その映画を見ませんでした。 — I didn't watch that film. (polite)

Polite Negative — ません and ませんでした

The polite negative is formed from the ます (masu) stem — the same stem used to build ます. Simply replace ます with ません (present) or ませんでした (past).

The polite negative past ませんでした is always written as one word. It does not change based on verb group — once you know the ます stem, simply swap ます for ませんでした.

The ある→ない Exception

ある (to exist / to have, for inanimate things) is a Group 1 verb — but it is the only one with an irregular negative. Normally, a godan verb ending in る would form its negative as 〜らない. But ある breaks this rule:

Common uses of ない as the negative of ある:

• 時間がない。 — There is no time. / I have no time.
• お金がない。 — I have no money.
• 問題がない。 — There is no problem.
• 昨日は授業がなかった。 — There was no class yesterday.
• 冷蔵庫に食べ物がありません。 — There is no food in the fridge. (polite)

This is why ない works double duty: it is both the standalone negative of ある ("there is no ~") and the negative suffix attached to other verbs (食べない). Context always makes the meaning clear.

5 Common Mistakes

1. Using あらない instead of ない. The verb ある is irregular in the plain negative. 本がある → 本がない ✓, never 本があらない ✗. Remember: only the polite form (ありません) follows the regular pattern.
2. Applying the Group 2 rule to Group 1 る verbs. Verbs like 帰る (return) and 走る (run) end in る but are Group 1. Their negative is 帰らない / 走らない, not 帰ない / 走ない ✗. Always identify the verb group first — consult a dictionary if unsure.
3. Forgetting the う→わ rule. Group 1 verbs ending in bare う change to わ, not あ: 買う → 買わない ✓, not 買あない ✗. This applies to 言う、会う、歌う、使う, and others.
4. Using しないです instead of しません in formal contexts. While しないです is grammatically acceptable, しません is the standard polite negative. In JLPT exams, writing or speaking contexts, prefer ません for consistent formal register.
5. Writing the negative past as ませんだった. The polite negative past is ませんでした — a single fixed ending. ませんだった ✗ does not exist. Think of ませんでした as one indivisible unit.

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