Overview
Japanese has similar parts of speech to English, but with important differences in how they function.
1. Nouns (名詞 - Meishi)
Definition: Words that name people, places, things, or concepts.
本 (hon) - book
東京 (toukyou) - Tokyo
学生 (gakusei) - student
愛 (ai) - love
Key Features
- Don't change form for plural
- No articles (no "a" or "the")
- Use particles to show grammatical role
本 (hon) = "book" or "books" or "the book"
Context determines specificity
Types
Common nouns: 犬 (dog), 車 (car)
Proper nouns: 日本 (Japan), 太郎 (Tarou)
Abstract nouns: 幸せ (happiness), 時間 (time)
See: Noun Basics for complete guide
2. Verbs (動詞 - Doushi)
Definition: Words that describe actions or states.
食べる (taberu) - to eat
行く (iku) - to go
ある (aru) - to exist
Key Features
- Always come at the end of the sentence/clause
- Conjugate for tense, politeness, negative
- Three groups: Godan, Ichidan, Irregular
食べる → 食べます (polite) → 食べない (negative) → 食べた (past)
Types
Action verbs: 走る (run), 書く (write)
State verbs: いる (exist - animate), ある (exist - inanimate)
Suru verbs: 勉強する (study), 運転する (drive)
See: Verb Basics for complete guide
3. Adjectives
Japanese has two types of adjectives, functioning differently from English adjectives.
I-adjectives (い形容詞)
End in い and conjugate like verbs:
大きい (ookii) - big
高い (takai) - tall/expensive
面白い (omoshiroi) - interesting
大きい → 大きくない (not big) → 大きかった (was big)
Na-adjectives (な形容詞)
Behave like nouns, add な before nouns:
静か (shizuka) - quiet
きれい (kirei) - beautiful/clean
便利 (benri) - convenient
静かな部屋 (shizuka na heya) - quiet room
Key Difference
I-adj: 大きい犬 (big dog) - no particle needed
Na-adj: 静かな犬 (quiet dog) - な required
See: Adjective Basics for complete guide
4. Particles (助詞 - Joshi)
Definition: Small words that mark grammatical relationships. No direct English equivalent.
は (wa) - topic marker
が (ga) - subject marker
を (wo) - object marker
に (ni) - location/direction/time
で (de) - location of action/means
と (to) - and/with
Key Features
- Don't translate directly to English
- Show word function in sentence
- Enable flexible word order
- Essential for correct grammar
私は本を読む
I (topic) book (object) read
"I read books"
See: Particles Overview for complete guide
5. Adverbs (副詞 - Fukushi)
Definition: Words that modify verbs, adjectives, or other adverbs.
ゆっくり (yukkuri) - slowly
とても (totemo) - very
よく (yoku) - often/well
全然 (zenzen) - not at all
Key Features
- Don't conjugate
- Usually come before what they modify
- Can be formed from adjectives
From i-adj: 早い → 早く (quickly)
From na-adj: 静か → 静かに (quietly)
Types
Time: 今 (now), 昨日 (yesterday)
Frequency: いつも (always), ときどき (sometimes)
Degree: とても (very), 少し (a little)
Manner: ゆっくり (slowly), 速く (quickly)
6. Copula (助動詞 - Jodoushi)
Definition: The verb "to be" in Japanese.
です (desu) - polite "is"
だ (da) - plain "is"
である (de aru) - formal "is"
Usage
私は学生です
"I am a student"
これは本だ
"This is a book"
Not a true verb - doesn't conjugate like action verbs.
See: です/だ Copula for complete guide
7. Pronouns (代名詞 - Daimeishi)
Definition: Words that replace nouns.
Personal Pronouns
私 (watashi) - I (neutral)
僕 (boku) - I (male, casual)
俺 (ore) - I (male, rough)
あなた (anata) - you (careful usage)
彼 (kare) - he
彼女 (kanojo) - she
Demonstratives (こそあど system)
これ (kore) - this
それ (sore) - that (near you)
あれ (are) - that (over there)
どれ (dore) - which
Key Feature
Pronouns are often omitted when clear from context:
何を食べますか？
"What will (you) eat?"
寿司を食べます
"(I) will eat sushi"
See: Pronouns for complete guide
8. Conjunctions (接続詞 - Setsuzokushi)
Definition: Words that connect clauses or sentences.
そして (soshite) - and then
しかし (shikashi) - however
でも (demo) - but
だから (dakara) - therefore
または (matawa) - or
Usage
雨が降った。だから、家にいた。
"It rained. Therefore, I stayed home."
Can also use て-form to connect:
雨が降って、家にいた
"It rained and I stayed home"
9. Counters (助数詞 - Josuushi)
Definition: Special suffixes used with numbers to count objects.
一つ (hitotsu) - one (general)
二人 (futari) - two people
三冊 (sansatsu) - three books
四匹 (yonhiki) - four small animals
Key Feature
Different counters for different object types:
本 (hon) - long objects
枚 (mai) - flat objects
匹 (hiki) - small animals
頭 (tou) - large animals
See: Counters for complete guide
10. Interjections (感動詞 - Kandoushi)
Definition: Expressions of emotion or reaction.
ああ (aa) - ah
おお (oo) - oh
えっ (e) - what? huh?
わあ (waa) - wow
Stand alone and don't modify other words.
Comparison to English
| Part of Speech | Japanese | English | Key Difference |
|---|---|---|---|
| Noun | 本 | book | No plural forms |
| Verb | 食べる | to eat | Sentence-final position |
| Adjective | 大きい/静か | big/quiet | Two types (i-adj, na-adj) |
| Particle | は、が、を | (none) | Unique to Japanese |
| Adverb | ゆっくり | slowly | Similar function |
| Copula | です/だ | is/am/are | Single form |
| Pronoun | 私 | I/me | Often omitted |
| Counter | 匹、枚 | (none) | Unique system |
Word Order by Part of Speech
[Time] [Topic] [Indirect Object] [Location] [Object] [Adverb] [Verb]
昨日 私は 友達に 図書館で 本を ゆっくり 読んだ
Each part of speech has its typical position, though order can vary.
Conjugating vs Non-Conjugating
Conjugate (Change Form)
- Verbs: 食べる → 食べます → 食べた
- I-adjectives: 大きい → 大きくない → 大きかった
- Copula: です → だ → でした
Don't Conjugate
- Nouns: 本 (always 本)
- Na-adjectives: 静か (always 静か, only add な/だ)
- Adverbs: ゆっくり (always ゆっくり)
- Particles: は、が、を (never change)
How They Work Together
私は 昨日 図書館で 面白い 本を ゆっくり 読んだ
Pronoun Adverb Noun+Ptcl I-adj Noun+Ptcl Adverb Verb
Topic Time Location Modifier Object Manner Action
Each part plays its role in creating meaning.
Key Takeaways
✓ Nouns don't have plural forms
✓ Verbs always come last
✓ Two types of adjectives (i-adj and na-adj)
✓ Particles are unique to Japanese
✓ Pronouns often omitted
✓ Counters required with numbers
✓ Understanding parts of speech helps build sentences correctly
Master these categories and their functions to construct grammatically correct Japanese sentences.
Next: Particles Overview
Deep Dives:
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