主Verbs and descriptions
は and が
は sets out what you're talking about. が points out something new. Once you see this, a lot of Japanese makes sense.
Start with a puzzle
A knock at the door. Which is the natural thing to say?
First
だれかは来ました。Dareka wa kimashita.Second
だれかが来ました。Dareka ga kimashita.The classic example
“A” and “the”, in a sense
Once there was a man.
He's new, so が, like “a man”.
The man was a doctor.
Now we know him, so は, like “the man”.
Which one?
Four rules that cover most cases
Question words like だれ, 何 and どこ can't take は as a subject, since they're unknown by definition.
| Use | When | Example |
|---|---|---|
| が | It's new to the conversation | 雨が降っています |
| は | It's already known, or anyone could identify it | 太陽は東から出ます |
| が | It's the answer to a “who” or “what” | だれが来ましたか。田中さんが来ました |
| が | It's in a clause inside a longer sentence | 私が読んだ本 |
は for contrast
It can also mean “this, unlike that”
Fish I eat, but meat I don't.
Yesterday I didn't go.
This hints you did go another day.
What happens to other particles
は replaces が and を, and joins the rest
は pushes out が and を: 本を読みました becomes 本は読みました when “the book” is the topic. It can also replace へ and location に. Other particles stay: 東京では, 友だちとは, 五時からは.
Inside a clause describing a noun, you won't normally find topic は. 私が読んだ本 is “the book that I read”, never 私は読んだ本.
Check yourself
Why は or が here?
Oh, it's raining!
Your turn
は or が?
Who opened the window?
Say it yourself
Who did it?
Your boss asks, “Who wrote this report?” You did it. Answer, then add that you're also the one who checked it.
Automatic feedback on your own answers is coming to Premium.