kono kikai wa sousa ga kantan nanode, setsumeisho o yomanakute mo tsukaemasu.

topic particle

Breakdown of kono kikai wa sousa ga kantan nanode, setsumeisho o yomanakute mo tsukaemasu.

• を: direct object particle
• 読よむ: to read
• が: subject particle

Questions & Answers about kono kikai wa sousa ga kantan nanode, setsumeisho o yomanakute mo tsukaemasu.

Why are there both は and が in この機械は操作が簡単なので?

They mark different things.

• この機械は = as for this machine
• 操作が簡単 = the operation is easy / using it is easy

So は sets the overall topic, and が marks what is specifically being described as easy.

A very literal breakdown is:

• この機械は = speaking of this machine
• 操作が簡単 = its operation is simple

This pattern is very common in Japanese:

• この店は値段が安い。
  As for this store, the prices are cheap.

• 彼は背が高い。
  As for him, his height is tall → He is tall.

So here, 機械 is the topic, while 操作 is the thing that is easy.

Why is it 操作が簡単 instead of 操作は簡単?

Because 操作 is the specific thing being identified as easy within the topic この機械.

Using が here sounds natural because it answers the idea of what is easy about this machine?
Answer: 操作が簡単.

If you said 操作は簡単, it would sound more contrastive, like:

• As for the operation, it’s easy
  (maybe implying something else is not easy)

So が is the neutral, natural choice here.

Why is there no の between 機械 and 操作? Shouldn’t it be something like この機械の操作?