Nai in Japanese can work as both an auxiliary verb and an i-adjective

What does “nai” mean in Japanese?

Japanese native speakers use “nai” mainly in the two different ways: as an auxiliary verb to add the meaning of ‘not’ to its preceding word; as an i-adjective to deny the existence of a thing. In this blog post, I will explain these two types of “nai”. And also, I will explain how to use them through example sentences. My explanations would help Japanese learners to use “nai” properly. Then, let’s get started!

Contents

• Nai as an auxiliary verb
  • Example #1: how to use “nai” as an auxiliary verb
• Nai as an i-adjective
  • Example #2: how to use “nai” as an i-adjective
• Summary

Nai as an auxiliary verb

Let me start with “nai” as an auxiliary verb. Below are the definition and meaning.

• nai – ない : an auxiliary verb used after a verb, adjective, or auxiliary verb to deny its meaning. Probably this is well known as a part of Japanese nai form.

Word orders in Japanese and English are different, but the role of this auxiliary verb is quite similar to that of “not” in English. To make negative expressions in Japanese, we need this auxiliary verb.

Unlike the other one explained later, this type of “nai” is normally written only in hiragana. So, it’s easy to differentiate them in writing. On this other hand, it would be a bit difficult in speaking. We need to be careful how they are used. If “nai” follows a verb, adjective, or auxiliary verb, most probably it would be an auxiliary verb.

Then, let me explain how to use “nai” as an auxiliary verb through the example sentence below.

Example #1: how to use “nai” as an auxiliary verb

Below are the new words used in the example sentence.

• kono – この : a determiner used before a noun which refers to a thing close to the speaker. In the example, this is used before “hana” to say “this flower” in Japanese.
• hana – 花 (はな) : a noun meaning ‘flower’ in Japanese.
• wa – は : a binding particle working as a case marker or topic marker. In the example, this is used after the noun phrase, “kono hana”, to make the subject in the sentence.
• utsukushiku – 美しく (うつくしく) : one conjugation of the i-adjective, “utsukushii“, which means ‘beautiful’ in Japanese. In the example, it has been conjugated for the better connection with the following auxiliary verb.

This is a typical usage of “nai”. In this example, this works as an auxiliary verb after the conjugated i-adjective, “utsukushiku”, to deny its meaning. When we want to deny the meaning of a verb, adjective, or auxiliary verb, we can use this “nai”. A preceding word needs to be conjugated properly, though.

Nai as an i-adjective

Next, let me explain “nai” as an i-adjective. Below are the definition and meaning.

• nai – 無い (ない) : an i-adjective used to deny the existence of a thing. It is often translated into English as ‘not to exist’, ‘not to have’, or ‘not to be’.

This is the other type of “nai”. It is often written in kanji. In addition, it is normally used as one individual word. So, its usage is, for sure, different.

Then, let me explain how to use this type of “nai” through the example sentence below.

Example #2: how to use “nai” as an i-adjective

Below are the new words used in the example sentence.

• watashi – 私 (わたし) : a pronoun meaning ‘I’ in Japanese.
• yume – 夢 (ゆめ) : a noun meaning ‘dream’ in Japanese.
• ga – が : a case particle used to make the subject word or the object word in a sentence. In the example, this is used after “yume” to make the subject word in the clause.

This is a typical usage of “nai” as an i-adjective. In this example, it is used to deny the existence of a dream. When we want to deny the existence of a thing in Japanese, this “nai” would be a good option.

Summary

In this blog post, I’ve explained the two different types of “nai” and how to use them through the example sentences. Let me summarize them as follows.

• nai – ない : an auxiliary verb used after a verb, adjective, or auxiliary verb to deny its meaning. Probably this is well known as a part of Japanese nai form. Word orders in Japanese and English are different, but the role of this “nai” is similar to that of “not”. This is written only in hiragana.
• nai – 無い (ない) : an i-adjective used to deny the existence of a thing. It is often translated into English as ‘not to exist’, ‘not to have’, or ‘not to be’. This is often written in kanji.

Hope my explanations are understandable and helpful for Japanese learners.