Help の "nominalizing": difference between のは and のが

[xminus1]

Hello, everyone:

Chapter 38 of the Minna textbook describes the use of の with various other particles as "の nominalizing".

Minna has two sentences to illustrate examples of のは and のが:
1) テニスをするのは面白いです
2) 東京の人は歩くのが速いです

I don't find Minna explicitly clear on explaining the distinction here between のは and のが , but looking at the sentences I am thinking that in sentence 1 the topic is the nominal phrase itself, "playing tennis", and so the topic marker は is used with の,

In sentence 2, the topic is "Tokyo people", and the construction with の is similar to a sentence like " 大阪は食べ物が美味しいです", where a topic is described using another noun with が and an adjective.

Is my thinking correct?

If not what is the best way to understand the difference between のは and のが in these examples?

Many thanks!

 

[Toritoribe]

Yes, your understanding is correct. It's quite the same as the difference between "noun + は" and "noun + が".

 

[xminus1]

That's a great way to look at it! It's really just the same old "noun + は" and "noun + が" concept! So simple. I love it.

Thank you!