The Simple Rule
は (wa) = Sets the topic/context ("Speaking of X...")
が (ga) = Identifies the subject (Who/what specifically)
Quick Decision Guide
Use が when:
├─ Existence (ある/いる)
├─ 好き/嫌い/できる/欲しい
├─ Answering who/what
├─ New information
└─ Subordinate clauses
Use は when:
├─ General statements
├─ Known information
├─ Contrasting
└─ Setting context
Side-by-Side Examples
Example 1: Liking Things
猫が好きです
"I like cats"
(Focus: what you like)
猫は好きです
"Cats, I like (but maybe not dogs)"
(Contrast implied)
Example 2: Identity
私が学生です
"I am the student" (me, not others)
私は学生です
"I am a student" (general fact about me)
Example 3: Existence
部屋に猫がいます
"There's a cat in the room"
(Must use が with いる)
猫は部屋にいます
"The cat is in the room"
(Topic: the cat)
When Only が Works
1. Existence Verbs
✓ 本があります
✗ 本はあります (wrong for existence)
2. Fixed Expressions
✓ 水が欲しい (want)
✓ 日本語ができる (can)
✓ 寿司が好き (like)
✗ Cannot use は here
3. Question Answers
Q: 誰が来ましたか？
A: 田中さんが来ました ✓
田中さんは来ました ✗
4. Subordinate Clauses
✓ 私が買った本
✗ 私は買った本
"The book I bought"
When Only は Works
1. Explicit Contrast
ビールは飲みますが、ワインは飲みません
"I drink beer but not wine"
(Cannot use が)
2. Topic Continuation
A: 田中さんはどこですか？
B: 田中さんは図書館です
(Continuing established topic)
Both Are Possible
Context changes meaning:
Scenario: Going Somewhere
私は行きます
"I will go" (neutral statement)
私が行きます
"I will go" (emphasis: me, not you)
Scenario: Weather
雨は降りません
"Rain won't fall (but maybe snow will)"
雨が降りません
"It won't rain" (neutral)
Double Particle Sentences
Both in one sentence:
私は猫が好きです
Topic Subject
"I (topic) like cats (subject of liking)"
象は鼻が長い
"Elephants (topic) have long trunks (subject)"
Common Patterns
| Pattern | Particle | Example |
|---|---|---|
| Existence | が | 本がある |
| Like/dislike | が | 寿司が好き |
| Can do | が | 日本語ができる |
| Want | が | 水が欲しい |
| General fact | は | 犬は動物だ |
| Contrast | は | ビールは飲む |
Practice Scenarios
Scenario 1: Self-Introduction
✓ 私は田中です
"I am Tanaka" (introducing yourself)
✗ 私が田中です (unless someone asked "Who's Tanaka?")
Scenario 2: Someone Asks "Who?"
Q: 誰が学生ですか？
A: 私が学生です ✓
"I am the student"
Scenario 3: Stating Preferences
✓ コーヒーが好きです
"I like coffee"
Not: コーヒーは好きです (implies contrast)
Scenario 4: Description
✓ この本は面白いです
"This book is interesting"
(Describing the topic)
Most Common Mistake
Using は with 好き/嫌い/できる:
Wrong: 寿司は好きです ❌
Right: 寿司が好きです ✓
Visual Summary
は (wa)
├─ "Speaking of X..."
├─ Sets context
├─ Known info
└─ Contrast
が (ga)
├─ Identifies who/what
├─ New info
├─ Answers questions
└─ With ある/いる/好き/できる
Key Takeaways
✓ が for existence, likes, abilities
✓ は for topics, general statements, contrast
✓ Match particles when answering questions
✓ Both can appear in same sentence
✓ Context determines which sounds natural
Deep Dive: