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“Nandayo”: Here’s What It Means

“Nandayo”: Here’s What It Means

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Phrases don’t always translate to exactly the same thing across languages, and sometimes a sentence is more than the words it contains.

The Japanese phrase 何だよ (nandayo) is a great example of this.


What does 何だよ (nandayo) mean?

The expression 何だよ (nandayo) literally means “what is [it].” 何 (usually なに but pronounced なん here) is the word for “what,” だ is the (basically is or are) and よ is the sentence-ending particle used to emphasize something.

The word “it” is in brackets because it’s the subject, which is implied and will very based on the context of the conversation.

Although this is a literal translation, a closer English equivalent of this phrase is probably “What the heck?”

In Japanese, 何だよ is really only used when you are surprised, upset or annoyed by something.

It can also be used in a similar way to the English expression “What’s your problem?” or “What is it with you?”

If the subject is not a person, “What’s up with [topic]?” might be more accurate. In some cases, 何だよ can even mean something like “Really?”


The parts of 何だよ

On the face of it, this phrase is pretty simple.

The first character is the kanji 何, which means “what.”

When used by itself, 何 is pronounced なに (nani). When combined with other words, however, the “i” sound is often dropped, leaving us with なん.

Next up is だ, the “casual” form of the copula です. (Yes, that means if you want to sound like a samurai you can say 「何でござる?!」 instead.)

It’s beyond the scope of this article to go into what the copula is, exactly. For our purposes here, it will suffice to note that it’s similar to “is” or “are” in English.

Finally we have よ, a sentence-ending particle used for emphasis and perhaps the simplest part of this phrase.

Put them all together and we have 「何だよ」.

Although it might be tempting to just translate this as “What is it,” that would not be a great translation.


Using 何だよ

The key to understanding 何だよ has little to do with the meaning of its individual pieces and everything to do with how it’s used.

Because だ is casual speech and よ emphasizes what the speaker is saying, adding だよ on the end of this phrase makes it informal and excited.

In practice, that means it comes across as a little rude most of the time.

Here, though, the tone you use will affect how what you say is understood.

If you’re obviously upset or angry about something, this phrase will absolutely be considered rude.

On the other hand, if you’re laughing before you say it chances are good it will be taken in a more relaxed way.

The other words that you pair with the phrase, or any context surrounding what you’re saying, will also play a role.

This means that it’s fairly easy to make sure you’re not misunderstood as being angry if you’re really just surprised.

The best way to really understand 何だよ is to look at these various contexts.


何だよ by itself

When said by itself, 何だよ definitely will depend on your tone of voice and facial expression.

This may seem confusing, but it really is no different from the word “What?” in English by itself.

For example, you might shout “What?!” in response to someone asking you questions over and over until you snap.

You might also laugh about something ridiculous you’ve seen and say “Whaaaat?” in a disbelieving tone of voice.

The possible meanings of just this single word are almost endless.

For this reason, it’s best to make sure you are examining context to properly understand it when others are using it.


何だよ with people

何だよ is frequently used to mean something like “What’s your problem?” or “What’s his problem?” It could even be used to refer to the speaker themselves, if paired with a pronoun for “I” or “me.”

Basically, if you are surprised or upset by something someone else has done and want to express that you’re mad, you can use this phrase.

A word of warning, though. Saying 何だよ to someone is pretty obnoxious, and if the person is particularly prone to violence they may be considered fighting words.

At the least, this is a kind of tough guy posturing normally unsuited for regular conversation.

In instances when you do hear this used to refer to people, the phrase will usually be followed by a pronoun or some other personal reference.

One neat thing about this phrase with people is that the type of pronoun used can give you a clue to the meaning.




Here, the very rude てめえ (“you”) is the pronoun. This person is super mad and probably ready for a fight. He is probably male, and may be drunk.


“What’s the president’s deal anyway?”

This is a much softer expression. The person is probably looking for gossip, rather than a fistfight.


何だよ with things or events

One common way Japanese people will use this phrase is in reference to things or events.

If 何だよ is preceded or followed by a reference to a specific topic, the person speaking is not really asking “what,” but rather something closer to “Why is [topic] like this?”

For example, if the reference is to a bus, the question should not be translated as “What is this bus?” but something like “What’s up with this bus?”




“What is this?”

Again, the sentence order is reversed from written Japanese in a way that is fairly typical of colloquial speech.

これは (this is) comes at the end of the sentence, with the particle は makes it clear that これ is the topic.

For references to things or events, tone of voice will play a large role in determining the English translation.

If the person saying this is obviously angry, the meaning will be closer to “What the hell is this?”


“What’s that person’s problem, anyway?”

The word もう is typically used by women, so this is unlikely to be delivered in too angry of a voice due to Japanese social norms. (Although of course, that doesn’t mean it’s impossible!)

Here there is no topic particle at all, another fairly typical habit of colloquial spoken Japanese.

All the same, it is fairly obvious that あいつの問題 (“that person’s problem”) is the topic of the speaker’s disgruntlement.


“Oh, what? Is that what that was?”

Unlike some of the other examples, where the tone of voice will play a large role in determining the meaning, it is hard to imagine someone saying this while angry.

The short あ (“Ah”) indicates mild surprise, while それだったっけ (“Is that what that was?”) is also a fairly relaxed-sounding expression. The っけ (-kke) suffix in particular implies a very casual self-questioning tone.

Here, the speaker has probably just had something which happened to them earlier and which they did not understand explained.

Maybe they were having trouble with a math problem which a classmate showed them how to do, or some other similar situation.


When not to use 何だよ

Although 何だよ is a pretty flexible expression, there are some situations where you definitely should not use it.

For the most part, this phrase should only be used in a casual conversational setting. For example, if you are hanging out with friends or chatting with someone in a bar or some other informal setting.

If you are at work or speaking with someone where you need to use more formal language such as the parent of a student you teach or a customer at a store where you are employed, you should definitely not try out this phrase.

At best, it will give the person to whom you are talking a poor impression of your social skills, and at worst it may really offend someone.

In these more formal situations, you would typically be expected to express no surprise at all.

If you absolutely need to say something to a person about their behavior in a formal setting, the very meek 「あの、すみませんですが。。。」 will do the trick.

Although this phrase technically means “Excuse me,” it is a common way for Japanese people to express that someone is doing something unexpected and unappreciated.

Of course, if the person you are talking to is angry, you may very well hear them say 「何だよ?!」 in response.