Japanese Slang 101 That Will Make You Sound Like a Local

  • July 11, 2020 / Queenie Kawabe

When we start studying Japanese, we usually begin with polite Japanese. This is both because polite Japanese is more straightforward and quicker to learn than colloquial or casual Japanese, and because for travel purposes it’s always good to be polite!

However, if you’re traveling in Japan or simply watching and listening to Japanese media at home, it won’t be long before you encounter a lot of slang. Slang is the fun part of the language! But, sometimes the meaning and usage of slang can be a little unclear, and textbooks usually aren’t much help.

In this blogpost, we’ll be going through a crash-course of some common informal contractions and exclamations. It is certainly not a complete list of slang you may come across — it’s a big language! — but we hope they are helpful! 

To view our other blogposts about Colloquial Japanese, click here!

To view our other blogposts about Japanese culture & travel, click here!


Informal Contractions

Informal contractions are words that, like going to –> gonna in English, get smushed together when we are speaking casually and/or quickly. 

Japanese, like any language, has tons of these! Below are some that are common enough that you will definitely see them showing up in subtitles and comic book dialogue.

Nani shiten da?
What are you doing? 

There are actually a few layers of contraction in this phrase. 

The polite version of the phrase would be: 

Nani o shite iru n desu ka?
What are you doing? 

The progressive tense (~ている ~te iru) often contracts to simply ~てる ~teru. When the inquisitive/explanative ending ~ん ~n is present (as in しているんです shite iru n desu), this sometimes contracts further (してんです shiten desu). In addition, in casual speech, many particles are dropped, and です desu is usually either dropped or switched to its Plain Form version, だ da, depending on the sentence. 

So, 何をしているんですか? Nani o shite iru n desu ka? becomes 何してんだ? Nani shiten da? 

Similar patterns can apply to many, many other verbs and verb phrases, too.

Nani miteru? (Nani o mite imasu ka?)
What are you looking at/watching?


ご飯、作ってんの?(ご飯作っているんですか?)( can also be used as an informal question or explanation particle). 
Gohan, tsukutten no? (Gohan o tsukutte iru n desu ka?)
Are you making food? 

(If you’d like more information on conjugating and using Plain Form (casual) verbs, click here!)

要らねえっつってんだろう! Iranee ttsu tten darou!



This initially looks like a string of nonsense!

But, when reconstructed into its non-slang state, it will become clearer what all the components are.

There are multiple informal contractions goin’ on here!

The more polite version of this phrase would be: 

Iranai to itte iru n deshou
I’m telling you, I don’t need/want [it].

In very casual speech, especially between boys or men having an argument or a person of any gender making an exclamation, vowel sounds sometimes combine together to make an ええ sound. So, 要らない iranai (don’t need, don’t want) becomes 要らねえ iranee

The ~と言って ~to itte (quotative particle + “to say” verb) in this particular phrase can also become smushed together, sometimes becoming ~っつって ~ttsutte

Lastly, as discussed above, 言っている itte iru can become 言ってる itteru when the progressive tense is contracted. Much like だ da is the Plain Form version of です desu, だろう darou is the Plain Form version of でしょう deshou, so the ending of the sentence changes from 言っているんでしょう itte iru n deshou to 言ってんだろう itten darou.


そーゆー So-yu-

Last and simplest but not least, this is a smushing of そういう sou iu (that kind of). 

Other words and phrases containing いう iu may also smush this way, for example どーゆー do-yu-どういう dou iu, what kind of)!


This is the fun section! No grammar here — just exclamations you may hear people using.

すごい Sugoi

This expression is one you’ve almost undoubtedly heard before. 

Like many slang terms, すごい sugoi is very multi-purpose. If you look it up in the dictionary, you’ll find its definitions include both “wonderful, amazing,” “vast in number,” and “terrible”! Generally speaking, it’s used as an exclamation to show that something has impressed you (sometimes in a good way, sometimes in a bad way). 

Important variations: 

As mentioned above, vowels may slur together into an ええ sound in casual speech, especially if the person speaking is exclaiming something or if two people are fighting. So, すごい sugoi is sometimes pronounced すげえ sugee.

You may also hear people adding ~じゃん ~jan to the ends of exclamations like すごい sugoi.

~じゃん ~jan is a sort of informal contraction of じゃないですか janai desu ka (isn’t it). Grammatically speaking, one should not add this ending to an i-adjective, but after all, one hallmark of slang is not following grammar rules!

So, すごいじゃん sugoi jan is literally “isn’t it great?” and can make your exclamation a bit like a rhetorical question, somewhat similarly to adding the particle ね ne to the end of an exclamation (or ordinary sentence).


ださい Dasai 

This expression means “uncool”! 

It can sound a bit harsh depending on who you’re saying it to, so be careful. 

When its vowels get smushed together, it becomes だせえ dasee.


やばい Yabai



This expression literally means “dangerous,” but like すごい sugoi its actual uses are very broad. Its most frequent use is to express one’s surprise at how [adjective] something is (wow, so delicious!; wow, so cold!; wow, so cheap!; etc). It can be used to express that something is good, or bad; depending on the context

You can also use it to actually express that something dangerous is happening, e.g. the microwave just caught fire.

When its vowels get smushed together, it becomes やべえ yabee.


知るか Shiru ka

This expression literally means “Do I know?” and is used in an exasperated or pretend-exasperated way when someone asks you something you have no answer to, or tells you something you don’t care about. It goes without saying that this is rude; so we recommend using it for reference only and not in your own conversation!

Variations that are somewhat less rude-sounding

知らん Shiran (a shortening of 知らない shira nai, this is used simply to express “I don’t know.”)

分かんない Wakannai (a smushing of 分からない wakara nai, used simply to express “I don’t know” or “I don’t understand”).

That’s all on slang expressions for now!

But, we will likely be publishing some more slang guides in the future with additional categories of slang words and phrases, so if you come across any terms you’d like us to cover leave a comment below! 

Also, as always, if you have any questions or suggestions, please let us know in the comments! We are a small team and so sometimes it does take us a while to reply, but we see and appreciate every single comment 🙂


Want to practice your Japanese slang and speaking skills with other learners around the world? Click here to check out our weekly Fluent Japanese Conversation Club (FJCC)!

If you’re studying for the JLPT, you can also click here to check out our Fluent Japanese Club (FJC), a customizable learning program that focuses on JLPT grammar and reading/writing skills.


To view our other blogposts about Colloquial Japanese, click here!

To view our other blogposts about Japanese culture & travel, click here!




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