信じられない
shinjirarenai
In Japanese, unbelievable is said as 信じられない (shinjirarenai).
信じられない is used as an adjective to describe something incredible or as a standalone exclamation to express shock, disbelief or even admiration, depending on the tone of voice. In informal settings among friends, the word まさか can also be used to carry a sense of disbelief and express surprise.
Meaning: incredible (adj)
Is there a formal and an informal way to say it?
The standard form 信じられない is the plain or informal version. For a polite way to say the phrase, you can add masen to the end to make it 信じられません. In very casual speech, you can add yo to the end to create 信じられないよ.
How does it change in a sentence?
信じられない is the plain/informal form and can function as either an adjective or an exclamation.
How do you pronounce it?
shinjirarenai
Did you know?
- The root verb 信じる comes from the kanji 信, which consists of the radicals for 'person' and 'word', visually representing the idea of trusting someone's word.
- If you are shocked by someone's behavior, saying 信じられない can sound much more judgmental than the English 'unbelievable', which is often used as a lighthearted exclamation.
- When expressing that a situation is 'unbelievable' due to being too good to be true, Japanese speakers might use 夢のようだ, which literally means 'it is like a dream'.
Examples in context
- 信じられないわ。It's unbelievable.This sentence shows how to use 信じられない to express that something is unbelievable.Tatoeba #145730 by bunbuku, translation #268832 by CK
- 信じられないような文化的退廃、驚くほどの無知、理想ばかりのガラクタ、真実を隠蔽する政策がアメリカの保守層のあいだでもっとも根強い支持を得ているのだ。Unbelievable cultural decline, stupendous ignorance, idealistic rubbish, and obscurantism find their strongest support among American reactionaries.This sentence shows 信じられない used as an adjective to describe unbelievable cultural decline.Tatoeba #5651900 by yamashin, translation #4772005 by Feryll
- 信じられない！Unbelievable!This sentence shows 信じられない used as a standalone exclamation.Tatoeba #342138 by grantortino, translation #268828 by CM
- そのニュースは信じられないですね。That news is unbelievable, isn't it?
- まさか彼女がそんなことを言うとは！I can't believe she would say such a thing!
- 彼のスキルは信じられないよ！His skills are unbelievable!
Example conversation
Ren and Himari are talking about a surprise party.
- 蓮 Ren昨日のパーティー、本当に信じられないだったね。Kinou no paatii, hontou ni shinjirarenai datta ne.Yesterday's party was truly unbelievable, wasn't it?
- 陽葵 Himariうん、あんなに豪華だとは思わなかったよ。Un, anna ni gouka da to wa omowanakatta yo.Yeah, I didn't think it would be that luxurious.
- 蓮 Renみんなが協力して準備したなんて信じられない。Minna ga kyouryoku shite junbi shita nante shinjirarenai.It's unbelievable that everyone cooperated to prepare it.
- 陽葵 Himari本当に最高のサプライズだったね。Hontou ni saikou no sapuraizu datta ne.It really was the best surprise.
Sources
- Wiktionary, “unbelievable” translations, CC BY-SA 4.0, dump of 2026-09-26.
- Example sentences: Tatoeba CC BY 2.0 FR.
