Polite vs Plain Form: Choosing Style by Situation [JLPT N4]
By Nihongo to Japan · Updated July 3, 2026
「食べます・食べる」「行きました・行った」「どうですか・どう？」 — switching styles by situation.
Polite vs Plain Form: Choosing Style by Situation
Japanese style splits into polite (ていねい体) and plain (常体), switched by situation: polite = ending in です・ます (食べます, 行きました, どうですか), for first meetings, the workplace, toward superiors/clients, formal occasions; plain = ending in だ・plain form (食べる, 行った, どう?), for friends, family, SNS diaries, inner thoughts. E.g. at work 「今から行ってきます」, with friends 「今から行ってくる」. ⚠️ Core principle: choose the style by listener and situation, and keep it consistent throughout (don't mix). ⚠️ The plain form has colloquial contractions (食べている→食べてる, ています→てます).
🧠 Core nuance: by situation and listener, switch polite or plain
The core is choosing the right style by situation, listener, and keeping it consistent throughout: ① polite (です・ます) — polite, with distance, for: first meetings, the workplace/business, toward superiors/bosses/clients, formal letters, interviews (食べます, 行きました, よろしくお願いします); first meetings may even use humble language (田中と申します); ② plain (普通形・だ) — close, casual, for: friends, family, partners, SNS diaries, inner monologue, novels/papers (食べる, 行った, どう?, 何した?). ⚠️ Core situational contrast: workplace/toward superiors 「今から行ってきます」 (polite) vs friends 「今から行ってくる」 (plain), 「今日何しましたか」 (polite) vs 「今日何した?」 (plain). ⚠️ The plain form has colloquial contractions (食べている→食べてる, 食べています→食べてます, 〜ておく→〜とく), more casual. ⚠️ Core principle: keep the style consistent throughout — within one conversation/text, polite stays all polite, plain stays all plain; mixing sounds unnatural. ⚠️ Uncertain of the relationship or situation → polite is safer and courteous. The foundation of appropriate N4 expression.
📌 Style Comparison
| Situation | Polite | Plain |
|---|---|---|
| first meeting/workplace | 行きます(○) | 行く(✗ rude) |
| friends/family | — | 行く(○) |
| past | 食べました | 食べた |
| question | どうですか | どう? |
| colloquial contraction | — | 食べてる(←食べている) |
💬 Example Sentences
- (first meeting) はじめまして、田中と申します。よろしくお願いします。 — polite (formal)
- (friends) 今日、何した? 暇?(What did you do today? Free?) — plain
- (to a boss) 今から取引先に行ってきます。(I'm off to the client now.) — polite
- (SNS diary) 今日は疲れた。早く寝よう。(I'm tired today. Let's sleep early.) — plain
- (friends) もう食べてる?(Are you already eating?) — plain contraction
🔄 Compare: polite vs plain vs contraction vs honorific/humble
| Style | Situation | Example |
|---|---|---|
| polite (です・ます) | workplace, toward superiors, first meetings | 行きます |
| plain (だ・plain form) | friends, family, SNS, diaries | 行く |
| colloquial contraction | casual speech | 食べてる, てます |
| honorific/humble | toward clients, bosses (above polite) | 申します, いらっしゃる |
⚠️ Common Mistakes
- Keep the style consistent: within one conversation/text, don't mix polite and plain (sounds unnatural).
- Workplace/superiors use polite: first meetings, workplace, superiors use polite; ✗ plain (rude).
- Contractions only for casual speech: 食べてる, てます are for casual settings; formal uses full polite.
- Uncertain → polite: when uncertain of the relationship or situation, polite is safer and courteous.
💡 Nuance & When to Use
Japanese style splits into polite (です・ます, polite with distance: workplace/superiors/first meetings) and plain (普通形・だ, close casual: friends/family/SNS/diaries). Switch by situation: workplace/superiors use polite, friends/close use plain. The plain form has colloquial contractions (食べてる, てます). ⚠️ Core principle: keep the style consistent, don't mix; uncertain → polite is safer. Toward clients/bosses, add honorific/humble. The foundation of appropriate N4 expression. A must.
🎯 JLPT Exam Tips
- N4 core: polite (です・ます, workplace/superiors/first meetings), plain (普通形・だ, friends/family/SNS).
- Core principle: choose the style by listener/situation, and keep it consistent, don't mix!
- Extension: plain colloquial contractions (食べてる, てます); toward clients/bosses use honorific/humble (above polite).
🖊️ Practice Quiz
Q1. When introducing yourself to someone for the first time, which register is appropriate?
(A) plain (田中だ。よろしく。)
(B) polite (田中と申します。よろしくお願いします。)
(C) either is fine
(D) depends
Q2. Conversation with a friend: 「今日何___？」(what did you do today?)
(A) しましたか (B) された？ (C) した？ (D) されましたか？
Q3. What is the colloquial plain contraction of 「食べています」?
(A) 食べてます (B) 食べてる (C) 食べる (D) 食べた
Q4. When writing a diary on social media, which register is generally used?
(A) polite (ます・です)
(B) plain (〜だ・〜た・dict. form)
(C) keigo (honorific/humble)
(D) classical/literary
Q5. Contacting your boss: 「今から___。」(reporting that you're going now)
(A) 行くよ (B) 行ってくる (C) 参ります (D) 行っちゃう
Answer Key
1. (B) ── a first-time self-introduction must use the polite register (ます・です), with humble forms (申します); plain would be rude.
2. (C) した？ ── friends use the plain register: 今日何した？
3. (B) 食べてる ── the plain colloquial contraction drops い: 食べている → 食べてる. (食べてます is the polite contraction.)
4. (B) ── social-media diaries generally use the plain register (〜だ/〜た/dict. form).
5. (C) 参ります ── to a boss, use the humble 参ります (humble of 行く).