のが - no ga
 

Hi everyone,

I learn my Japanese vocabulary with iKnow / smart.fm and also get sample sentences to each word.

Now, there's this sentence:

彼は走るのが速い。 (He runs fast.)

I know the meaning of each word and particle. But, I don't understand the combination of の and が together.

Thanks for your help.

First, think of them as two separate particles. When you have mastered their usages, you may remember them as a unit if you have to. Native speakers don't think of のが as a unit if that means anything.

The の is used for verb nominalization here. Needless to say, the verb is the 走る.

The が here is an identifier. It sort of answers a silent (or asked) question. "What does Bob do fast?" ---> "It's running that he does fast."
_________

「彼は速く走る。」 is a grammatical sentence but you won't hear a native speaker say it. It sounds very "translated".

We usually would prefer saying 「彼は走るのが速い。」.　

On the subject of nominalisation, I am getting my の and こと confused. Is there a simple rule of thumb for when to use one or the other?

Not only のが, but also のは、のを、のに、のも are used substitute of "こと".

彼は走るのが速い。and 彼は走ることが速い。are same meaning.
(but の is more natural for spoken language.)

彼は走るのは嫌いじゃない。
彼は走るのをやめない。
彼は走るのに夢中だ。
彼は泳ぐのも速い。
These are all OK and sound natural. and these are also OK if clause is picked out.

彼は速い。　（何が？）　走るの（こと）が。
彼はやめない。　（何を？）　走るの（こと）を。
彼は夢中だ。　（何に？）　走るの（こと）に。
彼は速い。　（何が？）　泳ぐの（こと）も、走るの（こと）も。

Ah, thanks for clarifying that out! :)

(And also for the other thread)

Thank you guys for answers!

jpallan

There's a rule for when to use の and when to use こと for the nominalization of a verb, but I don't remember it properly. This paper claims two things: (1) の is used for spatio-temporal clause nominalization (泳ぐの) and こと is used for non-spatio-temporal clause nominalization (であること) and (2) の is used when the speaker things the clause is in the addressee's consciousness while こと is not.

The first is what I was taught (upon review), but the second description raises some interesting points. Read the paper to learn some interesting things about fine distinctions between the two.

Kylegoets,
In this usage, sometimes の indicates ところ、もの、ひと instead of こと.

from your paper example(1),
太郎が泳いでいるのを見た。this の is same with ところ.

Likewise,
ここのリンゴでおいしいのはどれですか？（の=もの=リンゴ）
友達にテニスをやっているのがいるよ。(の=ひと=ともだち)