Which one should you use?
While 本当に functions as an adverb to modify verbs or adjectives, the related form 確かに is used specifically to express 'certainly' or 'definitely' in the context of expressing agreement.
Is there a formal and an informal way to say it?
In casual speech, the long vowel is often shortened to the colloquial form ほんとに. For an informal way to express surprise or request confirmation, you can drop the particle に and the copula to use 本当？ or ほんと？ If you want to express 'very' or 'really' in a colloquial way, you can use めっちゃ.
Is it said differently in some regions?
The colloquial expression めっちゃ is commonly used in the Kansai region.
Related words
How does it change in a sentence?
The adverbial form 本当に is created by adding the particle に to the noun/adjectival noun 本当.
How do you pronounce it?
hontō ni
When do people say it?
When expressing surprise at new information or requesting confirmation, speakers may use 本当？, ほんと？ or へえ？
Did you know?
- The word 本当 is composed of two kanji characters meaning 'truth' and 'road' or 'way', literally suggesting the 'true path'.
- While 本当に is used nationwide, the colloquial めっちゃ originated from the Kansai dialect's word めちゃくちゃ, which means 'messy' or 'in shambles'.
- While 本当に is a standard way to say 'really', a Japanese speaker might respond to a surprising statement with only the sound へえ？, which functions as a way to say 'Really?' or 'Is that so?' through tone alone.
Examples in context
- 本当にお前？Is it really you?This sentence shows how to use 本当に to ask for identification.Tatoeba #11603889 by small_snow, translation #1886922 by CK
- 本当に大丈夫？Are you really OK?This sentence uses 本当に to inquire about someone's well-being.Tatoeba #8706020 by bunbuku, translation #2713745 by CK
- 本当に悪いね。It's really bad.This sentence uses 本当に to describe a bad situation.Tatoeba #8814813 by small_snow, translation #2249201 by CK
- 本当にありがとうございますThank you very much.
- 実際に行ってみましたI actually went and saw it myself.
- 確かにそうですThat is definitely true.
- 本当に美しい景色ですねThe view is really beautiful, isn't it?
- マジで信じられないI can't believe it, seriously!
- めっちゃおいしいIt's really delicious!
- 本当に驚きました！I was really surprised!
- マジで行きたい！I seriously want to go!
- そうなの？本当に？Is that so? Really?
- めっちゃ楽しかった！It was so much fun!
- 532 more sentences on Tatoeba
Example conversation
Hiroto and Himari are talking about a surprise party.
- 大翔 Hiroto本当に明日パーティーがあるの？Hontou ni ashita paatii ga aru no?Is there really a party tomorrow?
- 陽葵 Himariうん、秘密だったんだけどね。Un, himitsu datta n dakedo ne.Yes, but it was supposed to be a secret.
- 大翔 Hiroto本当に？楽しみだな！Hontou ni? Tanoshimi da na!Really? I'm looking forward to it!
- 陽葵 Himari私も楽しみだよ。Watashi mo tanoshimi da yo.I am too.
Sources
- Wiktionary, “really” translations, CC BY-SA 4.0, dump of 2026-09-26.
- Example sentences: Tatoeba CC BY 2.0 FR.
