Oyasuminasai: a Japanese phrase for ‘good night’, explained

What does “oyasuminasai” mean in Japanese?

Native speakers say “oyasuminasai” to mean ‘good night’ in Japanese. Probably, many Japanese learners know this phrase well because it is often used in Japanese movies, songs, and the like and because it is one of the basic Japanese phrases. In this blog post, however, I will explain this phrase in detail based on its grammatical components. And also, I will explain its shortened version, “oyasumi”. My explanations would help Japanese learners to understand “oyasuminasai” and “oyasumi” more clearly. Then, let’s get started!

Contents

• Definition and meaning of “oyasuminasai”
• Breakdown of “oyasuminasai”
  • Example #1: how to use “oyasuminasai”
• Oyasumi: the shortened version of “oyasuminasai”
  • Example #2: how to use “oyasumi”
• Summary

Definition and meaning of “oyasuminasai”

Let me start with the definition and meaning of “oyasuminasai”.

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

This is a Japanese night greeting. Native speakers use this to say “good night” in Japanese.

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

Breakdown of “oyasuminasai”

“Oyasuminasai” consists of the following three components:

• o – お : a prefix used to make its following word polite.
• yasumi – 休み (やすみ) : a noun meaning ‘rest’ in Japanese.
• nasai – なさい : the command form of the verb, “nasaru”, which means ‘to do’ politely in Japanese. In reality, however, this is often translated into English just as ‘to do’, ‘to perform’, ‘to try’, ‘to have’, or such. This can also be found in other phrases like “gomennasai“.

From these three components, we can understand that “oyasuminasai” is literally a Japanese polite expression for ‘have a rest’. This literal interpretation is not completely in line with the meaning, but still very close, I think. Saying “good night” in Japanese is considered as saying “have a rest” politely at night.

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

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

Example #1: how to use “oyasuminasai”

Below are the new words used in the example sentence.

• mata – また : an adverb meaning ‘again’, ‘also’, or ‘too’ in Japanese.
• ashita – 明日 (あした) : a noun meaning ‘tomorrow’ in Japanese. This can also work as an adverb. In the example, this works together with “mata” to say “see you tomorrow” in Japanese. This is a kind of idiomatic expression.

This is a typical usage of “oyasuminasai”. Native speakers often use this example sentence as a night greeting to say “good night. see you tomorrow” in Japanese. It’s worth knowing, I think.

So far, I’ve explained the definition and meaning of “oyasuminasai” and how to use it through the example sentence. In more casual situations, however, native speakers tend to use the shortened version, “oyasumi”. Let me explain it as follows.

Oyasumi: the shortened version of “oyasuminasai”

Below are the definition and meaning of “oyasumi”.

• oyasumi – お休み (おやすみ) : the shortened version of “oyasuminasai”. So, this is a Japanese phrase for “good night”.

Japanese native speakers tend to use this in casual situations, for example, conversations with their friends and family members.

The last example sentence can be paraphrased with this shortened version as follows.

Example #2: how to use “oyasumi”

This is a typical usage of “oyasumi”. The English translation is still the same, but this Japanese sentence sounds more casual than the last one. So, we need to be careful with its use. We should use the longer version at least when we need to say “good night” to, for example, first-met people. I’m not sure if such a situation does really exist, though.

“Oyasumi” is the shortened phrase to say “good night” in Japanese. From its components, however, it can also be considered as just a polite expression for ‘rest’ in Japanese. And actually, it is. Normally, we can understand its correct and intended meaning from the situation and context. Still, we need to be careful with its use.

Summary

In this blog post, I’ve explained the definition and meaning of “oyasuminasai” in detail based on its grammatical components. And also, I’ve explained its shortened version, “oyasumi”. Let me summarize them as follows.

• oyasuminasai – お休みなさい (おやすみなさい) : a Japanese phrase for ‘good night’. This is a polite expression for ‘have a rest’ in Japanese. So, saying “good night” in Japanese can be considered as saying “have a rest” politely at night.
• oyasumi – お休み (おやすみ) : the shortened version of “oyasuminasai”. So, this is a Japanese phrase for “good night”. Japanese native speakers tend to use this version in casual situations. This can literally mean ‘rest’ as well. So, we need to be careful with the situation and context where this is used.

Hope my explanations are understandable and helpful for Japanese learners.