Nan sai desu ka is the Japanese phrase for ‘how old are you?’

How to say “how old are you?” in Japanese

Native speakers often say “nan sai desu ka” to mean ‘how old are you?’ in Japanese. Perhaps, some Japanese learners know this phrase as it is sometimes used in Japanese conversations. In this blog post, however, I will explain this phrase in detail based on its grammatical components. And also, I will explain how to use it through an example sentence. My explanations would help Japanese learners understand “nan sai desu ka” more clearly. Then, let’s get started!

Contents

• Definition and meaning of “nan sai desu ka”
• What does “nan sai desu ka” literally mean?
  • Example #1: how to say “how old are you?” in Japanese
• Definition and meaning of “oikutsu desu ka”
• What does “oikutsu” mean in Japanese?
  • Example #2: how to use “oikutsu desu ka”
• Summary

Definition and meaning of “nan sai desu ka”

Let me start with the definition and meaning of “nan sai desu ka”.

• nan sai desu ka – 何歳ですか/何才ですか (なんさいですか) : a phrase meaning ‘how old are you?’ in Japanese.

This phrase has two different kanji expressions. The first one is more formal and polite; the second is less formal but more widely used.

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

What does “nan sai desu ka” literally mean?

“Nan sai desu ka” consists of the following four components:

• nan – 何 (なん) : an interrogative pronoun meaning ‘what’ in Japanese. This is often used in Japanese questions.
• sai – 歳/才 (さい) : a suffix meaning ‘age’ in Japanese.
• desu – です : an auxiliary verb used after a noun or adjective to make it polite. Probably, this is well known as a part of Japanese desu form. In the phrase, this is used after “nan sai” to make it sound polite.
• ka – か : a sentence-ending particle used at the end of a sentence to make a question. As the definition suggests, this is used at the end of the phrase to make the question.

From these four components, we can understand that “nan sai desu ka” is literally the polite phrase for ‘what age?’ in Japanese. This literal interpretation is very close to the actual meaning.

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 “nan sai desu ka” through the detailed check above.

So far, I’ve explained the definition and meaning of “nan sai desu ka” together with its grammatical components. Then, let me explain how to use it through the example sentence below.

Example #1: how to say “how old are you?” in Japanese

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.
• it – 言っ (いっ) : one conjugation of the verb, “iu“, which means ‘to say’ 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. In the example, this is used after “it” to make its past tense form, “it ta”.

This is a typical usage of “nan sai desu ka”. When we want to say “how old are you?” in Japanese, this phrase is a very good option.

So far, I’ve explained the Japanese phrase for “how old are you?” It can work in various situations. In more formal situations, however, its polite version is often preferred. Let me explain it next.

Definition and meaning of “oikutsu desu ka”

Below are the definition and meaning of “oikutsu desu ka”.

• oikutsu desu ka – おいくつですか : the polite version of “nan sai desu ka” which means ‘how old are you?’ in Japanese.

Native speakers use this phrase to ask someone’s age politely in Japanese.

The definition and meaning are simple and clear, I think. To understand this phrase more clearly, however, let me explain “oikutsu” in detail.

What does “oikutsu” mean in Japanese?

Grammatically, “oikutsu” consists of the following two components:

• o – お : a prefix making its following word polite.
• ikutsu – いくつ : a noun widely used to mean ‘what number’, ‘how many’, ‘how old’, or such in Japanese.

From these two components, we can understand that “oikutsu” is literally the Japanese polite word for ‘how old’. So, we can use it to ask someone’s age politely in Japanese.

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

Example #2: how to use “oikutsu desu ka”

Below are the new words used in the example sentence.

• shitsurei – 失礼 (しつれい) : a noun meaning ‘rudeness’ in Japanese. However, native speakers often use this to mean ‘excuse me’ especially in conversations.
• ga – が : a conjunctive particle used after a phrase or sentence to add the meaning of ‘but’, ‘yet’, ‘though’, ‘although’, or such. This can be used to join two sentences which have different or opposite meanings.

This is a typical usage of “oikutsu desu ka”. In this example, it works together with “shitsurei desu ga” to mean ‘excuse me, but how old are you?’ in Japanese. Native speakers often use this example sentence to ask someone’s age in formal situations. Unfortunately, however, its usage is not limited to asking someone’s age. From the grammatical point of view, “oikutsu” can also mean ‘how many’ in Japanese. Depending on the context and situation, therefore, this example sentence can mean ‘excuse me, but how many (things) ?’ politely in Japanese. We need to be careful with this fact.

Summary

In this blog post, I’ve explained the definition and meaning of “nan sai desu ka” in detail based on its grammatical components. And also, I’ve explained its polite version, “oikutsu desu ka”. Let me summarize them as follows.

• nan sai desu ka – 何歳ですか/何才ですか (なんさいですか) : a phrase meaning ‘how old are you?’ in Japanese. This phrase has two different kanji expressions. The first one is more formal and polite; the second is less formal but more widely used.
• oikutsu desu ka – おいくつですか : the polite version of “nan sai desu ka” which means ‘how old are you?’ in Japanese. This is preferred in more formal situations. We need to be careful with that fact that this can also mean ‘how many (things)?’ politely in Japanese depending on the context and situation.

Hope my explanations are understandable and helpful for Japanese learners.