Oyasumi and Oyasuminasai: Japanese phrases for ‘good night’

What do “oyasumi” and “oyasuminasai” mean in Japanese?

Native speakers use these two phrases often to mean ‘good night’ in Japanese. Perhaps, some Japanese learners know these phrases as both are sometimes used in Japanese movies, songs, novels, manga, anime, and the like. In this blog post, however, I will explain them in detail together with their grammatical background. And also, I will explain how to use them through example sentences. My explanations would help Japanese learners understand “oyasumi” and “oyasuminasai” more clearly. Then, let’s get started!

Contents

• Definition and meanings of “oyasumi”
• Definition and meaning of “oyasuminasai”
• What does “oyasuminasai” literally mean in Japanese?
• Oyasumi vs. Oyasuminasai: which to use
  • Example #1: how to use “oyasumi”
  • Example #2: how to use “oyasuminasai”
• Summary

Definition and meanings of “oyasumi”

Let me start with the definition and meanings of “oyasumi”.

• oyasumi – お休み (おやすみ) : a phrase meaning ‘good night’ in Japanese. This can also work as the polite expression of “yasumi” which means a ‘day off’ or ‘vacation’ in Japanese.

Native speakers use this phrase to say “good night” in Japanese. In addition, they use this as the polite expression of “yasumi” which is a noun meaning a ‘day off’ or ‘vacation’ in Japanese. So, we need to be a bit careful with the context and situation.

As a phrase, this is widely considered as the shortened version of the other one, “oyasuminasai”. Let me explain it next.

Definition and meaning of “oyasuminasai”

Below are the definition and meaning of “oyasuminasai”.

• oyasuminasai – お休みなさい (おやすみなさい) : a phrase meaning ‘good night’ in Japanese.

This can work in more or less the same way as the shortened version does. Like other longer phrases, however, “oyasuminasai” is widely considered more formal and polite.

The definition and meaning are simple and clear. To understand this phrase more clearly, however, let me explain its grammatical components in detail, one by one.

What does “oyasuminasai” literally mean in Japanese?

“Oyasuminasai” consists of the following three components:

• o – お : a prefix making its following word polite.
• yasumi – 休み (やすみ) : a noun meaning a ‘day off’, ‘vacation’, ‘rest’, or such in Japanese.
• nasai – なさい : the command form of the verb, “nasaru”, which politely means ‘to do’, ‘to perform’, ‘to have’, ‘to make’, or such in Japanese. This can also be found in other phrases like “gomennasai“.

These three components tell us that “oyasuminasai” literally means ‘have a rest’ politely in Japanese. This literal interpretation is not completely in line with the actual meaning, but still very close, I think. In Japanese, politely saying “have a rest” at night results in meaning “good night”.

When we meet new Japanese phrases, we should check their grammatical components in detail to understand their meanings clearly and deeply. In many cases, components tell us a lot about the meanings of the phrases they form. Actually, here, we could get the better understanding of “oyasuminasai” through the detailed check above.

Oyasumi vs. Oyasuminasai: which to use

So far, I’ve explained the definitions and meanings of “oyasumi” and “oyasuminasai” in detail. Next, let me explain which we should use. Again, but “oyasumi” is the shortened version of “oyasuminasai” and thus can sound less polite. So, we should stick to the longer one in more formal situations. In casual situations, however, the shortened one is very acceptable. We need to pick proper one depending on the situation.

Then, let me explain how to use “oyasumi” and “oyasuminasai” through the example sentences below.

Example #1: how to use “oyasumi”

Below are the new words used in the example sentence.

• mata – また : an adverb meaning ‘again’, ‘also’, ‘too’, or such in Japanese.
• ashita – 明日 (あした) : a noun meaning ‘tomorrow’ in Japanese. In the example, this works together with “mata” to mean ‘see you tomorrow’ in Japanese.

This is a typical usage of “oyasumi”. When we want to say “good night” in casual situations in Japanese, this phrase is a good option.

Example #2: how to use “oyasuminasai”

Below are the new words used in the example sentence.

• to – と : a case particle working as a quote marker. In the example, this works after the clause to indicate what she said.
• kanojo – 彼女 (かのじょ) : a pronoun meaning ‘she’ 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 “kanojo” to make the subject in the sentence.
• kotae – 答え (こたえ) : one conjugation of the verb, “kotaeru”, which means ‘to answer’ in Japanese. In the example, it has been conjugated for the better connection with its following word.
• ta – た : an auxiliary verb used after a verb, adjective, or auxiliary verb to make its past tense form. Probably, this is well known as a part of the Japanese ta form. In the example, this is used after “kotae” to make its past tense form, “kotae ta”.

Summary

In this blog post, I’ve explained the definitions and meanings of “oyasumi” and “oyasuminasai” in detail together with the grammatical background. And also, I’ve explained how to use them through the example sentences. Let me summarize them as follows.

• oyasumi – お休み (おやすみ) : a phrase meaning ‘good night’ in Japanese. This can also work as the polite expression of “yasumi” which means a ‘day off’ or ‘vacation’ in Japanese. This is widely considered as the shortened version of the other one, “oyasuminasai”.
• oyasuminasai – お休みなさい (おやすみなさい) : a phrase meaning ‘good night’ in Japanese. This phrase literally means ‘have a rest’ politely in Japanese. This literal interpretation is not completely in line with the actual meaning, but still very close, I think. In Japanese, politely saying “have a rest” at night results in meaning “good night”.

Hope my explanations are understandable and helpful for Japanese learners.