How to form negative and past sentences in Japanese

To form negative and past sentences in Japanese, here is a concise guide:

Negative Sentences in Japanese

• Verbs are negated by changing their endings depending on their group:
  • Godan verbs (う-verbs): change the verb ending according to a pattern and add ない (nai). For example, 書く (kaku, “to write”) becomes 書かない (kakanai, “do not write”).
  • Ichidan verbs (る-verbs): drop the る (ru) and add ない (nai). For example, 食べる (taberu, “to eat”) becomes 食べない (tabenai, “do not eat”).
• For the copula です (desu), replace it with ではありません (de wa arimasen) for a formal negative or じゃないです (janai desu) more casually. For example, これは本です (kore wa hon desu, “This is a book”) becomes これは本ではありません (kore wa hon de wa arimasen, “This is not a book”). ^{1, 3}

Past Negative Sentences in Japanese

• The past negative form is created by taking the negative form of the verb (which ends with ない), removing the い (i), and replacing it with かった (katta).
• For example:
  • 飲まない (nomanai, “do not drink”) becomes 飲まなかった (nomanakatta, “did not drink”).
  • 食べない (tabenai, “do not eat”) becomes 食べなかった (tabenakatta, “did not eat”).
• This pattern works consistently for all verbs, including irregular ones.
• For です, the past negative form is ではありませんでした (de wa arimasen deshita) or じゃなかったです (janakatta desu) in casual speech. ^{2, 4, 6}

Summary Table of Verb Forms

This provides a practical framework to form both negative and past negative sentences in Japanese, suitable for everyday conversation and formal contexts.

References

• How to Use the Japanese Past Negative Verb Form なかった …

• Negative sentences in Japanese language (Nihongo)

• Past Tense – Learn Japanese

• Episode 16: Mastering Japanese Negative Sentences

• Grammar (1) - Lesson 4 - Language - Kids Web Japan

• Japanese Negation: Learn How to Form Negative Sentences

• Japanese Verb Negative Plain Past なかった Form

• Japanese Verb Negative Plain ない Form

• う-Verb (Negative-Past) (JLPT N5)