Casual Speech Patterns | Japanese Grammar Documentation

What is Casual Speech?

Casual speech (タメ口 tameguchi or 普通体 futsuu-tai) is the informal way Japanese people speak with friends, family, and close colleagues. It's characterized by:

Using plain verb forms instead of polite ます/です forms
Dropping particles
Shortened expressions
More direct language

When to use casual speech:

With close friends
With family members
Among people of similar age and status
In casual settings like bars, cafes with friends
In internal monologue

When NOT to use casual speech:

With strangers
In business settings
With teachers, bosses, or superiors
With customers or clients
When meeting someone for the first time

Basic Transformation: Polite → Casual

Verbs

Present affirmative:

Polite: 行きます (ikimasu) → Casual: 行く (iku)
"go/will go"

Polite: 食べます (tabemasu) → Casual: 食べる (taberu)
"eat/will eat"

Polite: します (shimasu) → Casual: する (suru)
"do/will do"

Present negative:

Polite: 行きません (ikimasen) → Casual: 行かない (ikanai)
"don't go/won't go"

Polite: 食べません (tabemasen) → Casual: 食べない (tabenai)
"don't eat/won't eat"

Polite: しません (shimasen) → Casual: しない (shinai)
"don't do/won't do"

Past affirmative:

Polite: 行きました (ikimashita) → Casual: 行った (itta)
"went"

Polite: 食べました (tabemashita) → Casual: 食べた (tabeta)
"ate"

Polite: しました (shimashita) → Casual: した (shita)
"did"

Past negative:

Polite: 行きませんでした (ikimasen deshita) → Casual: 行かなかった (ikanakatta)
"didn't go"

Polite: 食べませんでした (tabemasen deshita) → Casual: 食べなかった (tabenakatta)
"didn't eat"

Polite: しませんでした (shimasen deshita) → Casual: しなかった (shinakatta)
"didn't do"

Copula (to be)

Present affirmative:

Polite: 学生です (gakusei desu) → Casual: 学生だ (gakusei da)
"is a student"

Even more casual: 学生 (gakusei)
Just drop だ entirely in conversation

Present negative:

Polite: 学生じゃないです (gakusei janai desu) → Casual: 学生じゃない (gakusei janai)
"is not a student"

Alternative: 学生じゃありません → 学生じゃない

Past affirmative:

Polite: 学生でした (gakusei deshita) → Casual: 学生だった (gakusei datta)
"was a student"

Past negative:

Polite: 学生じゃなかったです → Casual: 学生じゃなかった (gakusei janakatta)
"was not a student"

Adjectives

い-adjectives:

Polite: おいしいです (oishii desu) → Casual: おいしい (oishii)
"is delicious"

Polite: 高いです (takai desu) → Casual: 高い (takai)
"is expensive"

Note: い-adjectives don't change much; just drop です.

な-adjectives:

Polite: 静かです (shizuka desu) → Casual: 静かだ (shizuka da)
"is quiet"

Polite: 便利です (benri desu) → Casual: 便利だ (benri da)
"is convenient"

Dropping Particles

In casual speech, particles are often dropped, especially を, に, and へ.

を Dropping

Formal: ご飯を食べる (gohan wo taberu)
Casual: ご飯食べる (gohan taberu)
"eat rice/meal"

Formal: テレビを見る (terebi wo miru)
Casual: テレビ見る (terebi miru)
"watch TV"

に Dropping

Formal: 学校に行く (gakkou ni iku)
Casual: 学校行く (gakkou iku)
"go to school"

Formal: 家に帰る (ie ni kaeru)
Casual: 家帰る (ie kaeru)
"go home"

Particles that STAY

は, が, and で are usually kept, though は can be dropped in very casual speech:

私は学生 → 学生 (just "student" when obvious)
これが好き (kore ga suki) - が usually stays
図書館で勉強 (toshokan de benkyou) - で usually stays

Casual Question Forms

Dropping か

The question particle か is usually dropped in casual speech. Use rising intonation instead.

Formal: 行きますか？ (ikimasu ka?)
Casual: 行く？ (iku?)
"Are you going?"

Formal: これは何ですか？ (kore wa nan desu ka?)
Casual: これ何？ (kore nani?)
"What's this?"

Formal: 分かりますか？ (wakarimasu ka?)
Casual: 分かる？ (wakaru?)
"Do you understand?"

の for Questions

Add の (no) at the end for a softer, more casual question:

行くの？ (iku no?)
"Are you going?"

何してるの？ (nani shiteru no?)
"What are you doing?"

本当なの？ (hontou na no?)
"Is it true?"

More common in feminine speech, but used by everyone.

Common Casual Expressions

Greetings

おはよう (ohayou) - "Good morning" (casual)
おはようございます (ohayou gozaimasu) - polite version

やあ / よう (yaa / you) - "Hey"

元気？ (genki?) - "How are you?" / "You good?"
元気ですか？ (genki desu ka?) - polite version

Agreement/Acknowledgment

うん (un) - "Yeah" (casual)
はい (hai) - "Yes" (polite)

そうそう (sou sou) - "Yeah, yeah" / "Exactly"

だよね (da yo ne) - "Right?" / "Isn't it?"

まあね (maa ne) - "Well, yeah" / "I guess so"

Negative Responses

ううん (uun) - "Nah" / "No" (casual)
いいえ (iie) - "No" (polite)

ちがう (chigau) - "That's wrong" / "No, that's not it"

やだ (yada) - "I don't want to" / "No way"

Casual Invitations

行こう (ikou) - "Let's go"
行きましょう (ikimashou) - polite version

食べよう (tabeyou) - "Let's eat"

映画見ない？ (eiga minai?) - "Wanna watch a movie?"
映画を見ませんか？ (eiga wo mimasen ka?) - polite version

Sentence-Ending Patterns

よ (yo) - Emphasis/Information

Adds emphasis or provides new information:

これ、おいしいよ。
Kore, oishii yo.
"This is delicious!" (You should know)

もう帰るよ。
Mou kaeru yo.
"I'm leaving now." (FYI)

ね (ne) - Confirmation/Agreement

Seeks confirmation or agreement:

いい天気だね。
Ii tenki da ne.
"Nice weather, isn't it?"

難しいね。
Muzukashii ne.
"It's difficult, huh?"

よね (yo ne) - Combination

Expects agreement about information:

明日は休みだよね。
Ashita wa yasumi da yo ne.
"Tomorrow's a day off, right?"

彼は学生だよね。
Kare wa gakusei da yo ne.
"He's a student, right?"

な (na) - Reflection

Masculine casual reflection (softer than よ):

いい天気だな。
Ii tenki da na.
"Nice weather." (to oneself or casual company)

難しいな。
Muzukashii na.
"This is tough, man."

んだ/んです Forms in Casual Speech

の/ん for Explanation

In casual speech, のだ becomes んだ:

Formal: 明日は忙しいんです。
Casual: 明日は忙しいんだ。
Asu wa isogashii n da.
"The thing is, I'm busy tomorrow."

Formal: どうしてですか？
Casual: どうしてなの？
Doushite na no?
"Why is that?"

Question form: の？

どこ行くの？
Doko iku no?
"Where are you going?" (explanatory)

何してるの？
Nani shiteru no?
"What are you doing?" (seeking explanation)

Contractions in Casual Speech

ている → てる

Formal: 何をしていますか？
Casual: 何してる？
Nani shiteru?
"What are you doing?"

Formal: 食べています
Casual: 食べてる
Tabeteru
"I'm eating"

ては → ちゃ / では → じゃ

Formal: 食べてはいけません
Casual: 食べちゃダメ
Tabecha dame
"You can't eat that"

Formal: 見てはいけない
Casual: 見ちゃダメ
Micha dame
"You can't look"

ておく → とく

Formal: 読んでおきます
Casual: 読んどく
Yondoku
"I'll read it (in advance)"

Formal: やっておいて
Casual: やっといて
Yattoite
"Do it (in advance)"

See: Contractions for complete list

Real Conversation Examples

Example 1: Making Plans

A: 明日暇？
   Ashita hima?
   "Are you free tomorrow?"

B: うん、暇だよ。
   Un, hima da yo.
   "Yeah, I'm free."

A: 映画見に行かない？
   Eiga mi ni ikanai?
   "Wanna go see a movie?"

B: いいね！何時にする？
   Ii ne! Nanji ni suru?
   "Sounds good! What time?"

A: 3時でどう？
   Sanji de dou?
   "How about 3 o'clock?"

B: オッケー。駅で会おう。
   OK. Eki de aou.
   "OK. Let's meet at the station."

Example 2: Talking About Food

A: お腹すいた。
   Onaka suita.
   "I'm hungry."

B: 何食べたい？
   Nani tabetai?
   "What do you want to eat?"

A: ラーメンがいいな。
   Ra-men ga ii na.
   "Ramen would be good."

B: あそこの店、おいしいよ。
   Asoko no mise, oishii yo.
   "That shop over there is delicious."

A: じゃ、そこ行こう！
   Ja, soko ikou!
   "Then let's go there!"

Example 3: Casual Chat

A: 昨日何してた？
   Kinou nani shiteta?
   "What were you doing yesterday?"

B: ずっと家にいた。
   Zutto ie ni ita.
   "I was home the whole time."

A: 暇だったでしょ？
   Hima datta desho?
   "You were bored, right?"

B: まあね。でも映画見たから大丈夫。
   Maa ne. Demo eiga mita kara daijoubu.
   "Well, yeah. But I watched a movie, so it's fine."

Common Mistakes

Mistake 1: Using Casual Speech Too Early

❌ Meeting someone: よう！元気？ ✓ First meeting: はじめまして。元気ですか？

Wait until the relationship develops or until invited to use casual speech.

Mistake 2: Mixing Polite and Casual

❌ 今日は暇ですから、映画見る？ (です + casual verb)

✓ 今日は暇だから、映画見る？ (all casual) ✓ 今日は暇ですから、映画を見ませんか？ (all polite)

Keep the same level throughout.

Mistake 3: Dropping Essential Particles

❌ 私友達話す (watashi tomodachi hanasu) Confusing without particles

✓ 私は友達と話す (watashi wa tomodachi to hanasu) "I talk with my friend"

Some particles (は、が、と) are usually kept.

Mistake 4: Forgetting Rising Intonation

❌ 行く. (iku.) - Statement: "I'm going" ✓ 行く？ (iku?) - Question: "Are you going?"

In casual questions without か, intonation is crucial.

Practice Exercises

Exercise 1: Convert to Casual

Transform these polite sentences:

今日は忙しいですか？
コーヒーを飲みますか？
昨日映画を見ました。
明日学校に行きません。

Answers:

今日忙しい？
コーヒー飲む？
昨日映画見た。
明日学校行かない。

Exercise 2: Add Ending Particles

Add よ, ね, or よね to these sentences:

おいしい＿＿
難しい＿＿
明日は休み＿＿
もう帰る＿＿

Possible answers:

おいしいよ (telling new info)
難しいね (seeking agreement)
明日は休みだよね (confirming)
もう帰るよ (announcing)

Exercise 3: Create Casual Conversations

Make short dialogues about:

Asking a friend to hang out
Talking about what you did today
Discussing food preferences

Levels of Casualness

Even within casual speech, there are levels:

Level 1: Semi-casual

今日暇？ 映画見に行かない？
Keeps some structure, suitable for acquaintances

Level 2: Casual

暇？ 映画行く？
Drops more particles, close friends

Level 3: Very casual

暇？ 映画？
Minimal structure, very close friends/family

Adjust based on relationship closeness and context.

Summary

Aspect	Polite	Casual
Verbs	行きます	行く
Copula	です	だ (or drop)
Questions	か？	？ (intonation)
Particles	Usually kept	Often dropped
-ている	-ています	-てる
Tone	Formal	Direct

Key Points:

Use plain forms (dictionary form, ない, た, etc.)
Drop を, に, へ particles often
Use rising intonation for questions
Add よ, ね for nuance
Match casualness level to relationship
Never use with superiors or in formal settings

Mastering casual speech is essential for natural Japanese conversation, but always be aware of social context and use appropriate formality levels.