返信する

The Japanese verb 返信する (henshin suru) is a cornerstone of modern communication, specifically referring to the act of replying to a message, email, or digital correspondence. Etymologically, it is composed of two kanji: 返 (hen), meaning 'to return' or 'to give back,' and 信 (shin), which in this context refers to 'correspondence,' 'news,' or 'signal.' Together, they literally translate to 'returning a signal' or 'sending back a message.' In the digital age, this word has become ubiquitous, appearing on every 'Reply' button in Japanese software interfaces, from Gmail to LINE and Twitter (X). Unlike more general words for answering, 返信する specifically implies a written or electronic response. It carries a sense of formal completion in a communicative loop, where one party initiates contact and the other acknowledges and responds. Understanding this word is essential for anyone navigating professional or social environments in Japan, as the etiquette surrounding 'henshin' (the noun form) is a significant part of Japanese social harmony (wa).

Core Concept

The act of sending a written or digital response to a previously received communication.

Historically, before the internet, the word was used for telegrams and letters, but it has found its true home in the era of instant messaging. It is important to distinguish it from 答える (kotaeru), which means to answer a question or a challenge. While you might 'answer' a question within an email, the act of sending that email back is 'henshin.' In a business context, the speed of your 返信 can define your professional reputation. A 'soku-hen' (immediate reply) is highly valued, whereas 'henshin-busu' (someone who is slow to reply) is a modern slang term for someone who lacks digital punctuality. The word also encompasses the content of the reply itself when used as a noun. For example, 'henshin ga nai' means 'there is no reply.' This distinction between the action and the object is crucial for mastery.

Kanji Breakdown

返 (Return) + 信 (Message/Trust) = To return a message.

Furthermore, the word reflects the reciprocal nature of Japanese society. Communication is seen as a gift-giving process; when you receive a message, you owe a response. This is why the 'read' (既読 - kidoku) feature on apps like LINE is so stressful for many Japanese users; it creates an immediate social obligation to 返信する. In high-level Japanese, you might encounter 返信を差し上げる (henshin wo sashiageru), which is the humble form used when replying to a superior. Conversely, you might ask a superior for a reply using ご返信をいただければ幸いです (go-henshin wo itadakereba saiwaidesu). These variations show how the word scales from casual texts between friends to the highest levels of corporate diplomacy.

Usage Context

Emails, SMS, LINE, Social Media DMs, Letters, and Telegrams.

Using 返信する correctly involves understanding its grammatical structure as a 'suru' verb and its relationship with particles. The most common particle used with this verb is に (ni), which indicates the recipient of the reply or the specific message being replied to. For example, 'Tom-san ni henshin suru' (Reply to Tom) or 'meeru ni henshin suru' (Reply to the email). It is a transitive verb when you consider the 'reply' as the object, but it is most frequently used in its intransitive-like suru form where the action of replying is the focus. In formal writing, the prefix ご (go) is often added to the noun form to create ご返信 (go-henshin), showing respect to the other person's act of replying or requesting a reply from them.

Grammar Pattern

[Recipient/Message] + に + 返信する

When conjugating, follow the standard 'suru' patterns: 返信します (henshin shimasu) for polite present, 返信した (henshin shita) for casual past, and 返信しない (henshin shinai) for negative. In business emails, you will often see the humble form 返信いたす (henshin itasu) or 返信申し上げます (henshin moushiagemasu). For instance, 'O-isogashii tokoro osoreirimasu ga, go-henshin itadakereba saiwaidesu' (I am sorry to disturb you while you are busy, but I would be grateful if you could reply). This level of politeness is standard in Japanese corporate culture. On the other hand, in a casual LINE chat, you might simply say 'henshin okurete gomen!' (Sorry for the late reply!).

Conjugation Examples

Polite: 返信します | Negative: 返信しません | Past: 返信しました | Te-form: 返信して

Another important aspect is the speed of the reply. Japanese has specific adverbs to modify 返信する. 即座に (sokuza ni) or すぐに (sugu ni) are used for immediate replies. 折り返し (orikaeshi) is a very common business term meaning 'by return' or 'immediately back.' For example, 'Orikaeshi henshin itashimasu' means 'I will reply to you immediately.' If you are late, you should use 遅れて (okurete). The verb can also be used in the passive voice 返信される (henshin sareru) to describe being replied to, though this is less common than the active form. Usually, you would say 'henshin ga kuru' (a reply comes) instead of using the passive verb.

Common Adverbs

すぐに (immediately), 丁寧に (politely), 忘れて (forgettingly), 折り返し (by return).

You will encounter 返信する in almost every digital interaction in Japan. In the workplace, it is the standard term for email communication. During a meeting, someone might say, 'Ato de meeru de henshin shimasu' (I will reply via email later). On your smartphone, the button that says 'Reply' in English will be labeled 返信 in Japanese. It is also a frequent topic of conversation in social settings, particularly when discussing dating or friendships. People often complain about 'kidoku suruu' (reading a message and ignoring it/not replying), where the implied action they are failing to do is 返信する. In news reports about cyberbullying or social media trends, this verb is used to describe the flow of comments and responses.

Workplace Setting

Used in emails, Slack, Teams, and during discussions about client communication.

In the context of customer service, you will hear it in automated voice messages or see it in help center documentation. 'Henshin wa 24-jikan inai ni itashimasu' (We will reply within 24 hours). In schools, teachers might use it when talking about submitting forms or responding to digital assignments. Even in anime or dramas, a character might stare at their phone, debating whether to 返信する to a crush. The word is so integrated into daily life that it often appears in song lyrics about long-distance relationships or modern loneliness. It represents the bridge between two people in the digital void.

Social Media

Used for DMs, comments on posts, and replying to threads on platforms like X or Instagram.

Furthermore, in the world of recruitment and job hunting (shukatsu), the term is vital. Candidates are judged on how professionally they 返信する to interview invites. A common phrase is 'Go-henshin omachi shite orimasu' (I am looking forward to your reply). In this high-stakes environment, the word carries the weight of one's future career. Whether it's a casual 'un' (yeah) on LINE or a 500-word formal apology in a business email, the act is always 返信する.

Formal Announcements

'Please reply to this invitation by Friday' is 'Kinyoubi made ni go-henshin kudasai'.

One of the most frequent mistakes learners make is confusing 返信する with 答える (kotaeru). While both can be translated as 'to answer' in English, they are not interchangeable. 答える is used for answering a specific question, a quiz, or a phone call. You 'answer' (kotaeru) the phone, but you 'reply' (henshin suru) to a text message. If you say 'meeru ni kotaeru,' it sounds like you are answering a question contained within the email, rather than the act of sending the email back. Another common error is using 返す (kaesu) alone. While kaesu means 'to return' something physical (like a book), using it for messages is very casual (e.g., 'meeru wo kaesu'). In any semi-formal or formal situation, 返信する is the correct choice.

Mistake 1: Confusing with 'Kotaeru'

Incorrect: 質問に返信する (Reply to a question). Correct: 質問に答える (Answer a question).

Another nuance is the particle usage. Some learners use を (wo) instead of に (ni). While 'meeru wo henshin suru' is technically understandable, 'meeru ni henshin suru' is much more natural as it treats the email as the target of the response. Also, be careful with the honorifics. Using ご返信します (go-henshin shimasu) to describe your own action is a common 'double honorific' mistake (kenjougo confusion). You should say 返信いたします (henshin itashimasu) for your own action and reserve ご返信 (go-henshin) for the other person's action.

Mistake 2: Wrong Honorifics

Incorrect: 私がご返信します。 Correct: 私が返信いたします。

Lastly, learners often forget that 返信する implies a *written* medium. You cannot 返信する to someone speaking to you face-to-face. In that case, you would use 返事をする (henji wo suru) or 答える (kotaeru). If you are in a conversation and someone asks you something, and you say 'henshin shimasu,' it sounds like you are going to go away and send them a text message later rather than speaking to them now. This distinction between verbal and written response is a key marker of advanced proficiency.

Mistake 3: Medium Confusion

Use 'Henshin' for digital/written. Use 'Henji' for verbal/general.

While 返信する is the most common word for replying to messages, several other words share similar meanings but carry different nuances. Understanding these differences will help you choose the most appropriate term for the situation. The most frequent synonym is 返事をする (henji wo suru). While henshin is specific to digital or written messages, henji is much broader. It can mean a verbal 'yes,' a nod of the head, or a written letter. In casual conversation, people often say 'henji shite!' (Answer me!) regardless of whether it's a text or a spoken question. However, in a business email, henshin is the standard technical term.

返信する vs. 返事をする

Henshin: Digital/Written only. Henji: Verbal, Physical, or Written (General).

Another related word is 回答する (kaitou suru). This is used for providing an answer to a formal inquiry, a survey, or a specific question. It implies a more definitive or official answer than a simple 'henshin.' For example, a company 'kaitou' to a customer's complaint with an official statement. Similarly, 返答する (hentou suru) is used for giving an answer or a response, often in a more formal or serious verbal context. If a lawyer asks a question in court, the witness 'hentou' (responds). 応答する (outou suru) is used for 'responding' or 'reacting,' often in a technical or emergency context, like a pilot responding to a radio tower or a system responding to a command.

Comparison Table

回答 (Kaitou): Official answer/Survey. 返答 (Hentou): Formal verbal response. 応答 (Outou): Technical/Radio response.

Lastly, we have レス (resu), which is a shortened version of the English word 'response.' This is very casual and used almost exclusively in internet forums (like 2chan/5chan) or very informal group chats. You might hear 'resu ga hayai' (fast response). However, never use 'resu' in a business setting. There is also 折り返し (orikaeshi), which specifically refers to the act of 'replying back' immediately, often used for phone calls ('orikaeshi denwa shimasu') but also for emails. Mastering these nuances allows you to navigate the complex social layers of Japanese communication with precision.

Casual vs. Formal

Casual: レス、返事. Standard: 返信. Formal: ご返信、ご回答.