Polite (Teineigo) vs. Casual Japanese: When to Use Which
Using polite Japanese with your friends actually pushes them away. Learn how to calculate 'Social Distance' and switch to casual form.
Textbooks teach you to end every sentence with "Desu" or "Masu". But if you watch anime, talk to a Japanese friend, or go to an Izakaya, you will rarely hear those words. Japanese has two completely different modes of speaking: Casual Form (Tamego) and Polite Form (Teineigo).
The Social Distance Scanner
Choosing between Casual and Polite form is a real-time calculation of your "Social Distance" from the listener. It factors in age, hierarchy, relationship, and the setting. Choosing wrong can either make you sound incredibly rude, or weirdly distant and robotic.
The Forms at a Glance
| English | Casual (Dictionary Form) | Polite (Desu/Masu) |
|---|---|---|
| To Eat | 食べる (Taberu) | 食べます (Tabemasu) |
| To Go | 行く (Iku) | 行きます (Ikimasu) |
| It is a cat | 猫だ (Neko da) | 猫です (Neko desu) |
| I won't drink | 飲まない (Nomanai) | 飲みません (Nomimasen) |
When to Use Polite Form (Teineigo)
This is your default shield. If you are ever unsure, use Polite form. You should use it with:
- Strangers and shop staff.
- Coworkers (especially those older or senior to you).
- Acquaintances you aren't close with yet.
When to Use Casual Form (Tamego)
This is where true friendship happens. Using polite form with a close friend actually pushes them away, implying you aren't close enough yet. Use casual form with:
- Close friends and family.
- People younger than you (in casual settings).
- When talking to yourself (Inner monologue).
- Grammar structures: Many advanced grammar points require the verb to be in casual form before adding the grammar particle!
The Awkward Transition Phase
How to Switch from Polite to Casual
The Mixing Phase
As you become friends with an acquaintance, you might start mixing casual and polite forms. 'Kyou isogashii? Sou desu ne.' (Are you busy today? Yes, I am.)
The Permission Ask
Often, one person will explicitly ask: 'Keigo nuki ni shiyou?' (Shall we drop the polite language?). This is the green light for friendship.
Full Casual
You are now officially close friends. Using Desu/Masu now would be considered sarcastic or weird.
🗣️ Stop Sounding Like a Textbook
Traditional classes only teach Desu/Masu. LenGaki's conversation scenarios let you practice switching between Casual and Polite forms dynamically, depending on the AI character you are talking to.
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