kono tyuuko no kamera ha zyoutai ga ii desu.

Because 中古 is a noun here, not an -i adjective.

• 中古 = used / secondhand
• カメラ = camera

In Japanese, when one noun modifies another noun, の is often used:

• 中古のカメラ = a used camera
• literally: a secondhand camera

So の is linking 中古 to カメラ.

A learner might expect an adjective, but 中古 does not behave like 古い. You do not say 中古いカメラ.

Also, in real Japanese, 中古カメラ is possible too, especially in labels, ads, or compound-style expressions. But 中古のカメラ is very natural and clearer for learners.

They are doing different jobs.

• この中古のカメラは = as for this used camera...
• 状態がいいです = its condition is good

So the sentence structure is:

• Topic: this used camera
• Subject inside the comment: condition

This kind of pattern is very common in Japanese:

• A は B が いい
• As for A, B is good

Examples:

• この店はコーヒーがおいしいです。
  As for this shop, the coffee is delicious.
• 彼は頭がいいです。
  As for him, his brain/intelligence is good = He is smart.

So here, the camera is the overall topic, and 状態 is the thing specifically being described as good.

状態 means condition or state, and いい means good.

So 状態がいい means:

• is in good condition
• has good condition
• the condition is good

This is a very natural expression in Japanese, especially for things like:

• cameras
• cars
• books
• clothes
• electronics

For example:

• この本は状態がいいです。 = This book is in good condition.
• 中古なのに状態がいいです。 = Even though it’s used, it’s in good condition.

In English, we usually do not say the condition is good unless we want to sound a bit formal, but in Japanese this structure is completely normal.

You can say that, but it means something a little broader.

• この中古のカメラはいいです = This used camera is good.
• この中古のカメラは状態がいいです = This used camera is in good condition.

The version with 状態がいい is more specific. It focuses on the camera’s physical condition, not its overall quality.

So:

• いいです alone could mean it’s good in general
  • good quality
  • a good choice
  • nice
  • satisfactory
• 状態がいいです specifically means the condition is good

Both are related, and both can mean good.

• よい is the more basic/dictionary form
• いい is the very common everyday form

In modern Japanese, いい is usually what people say in ordinary conversation:

• 状態がいいです = normal and natural

But when the word changes form, it often goes back to the よ base:

• よくない = not good
• よかった = was good
• よければ = if it’s okay

So learners often memorize it like this:

• plain positive: いい
• many other forms: based on よい

That is why いいです is correct here.

Yes, いい is already the predicate because it is an -i adjective.

In plain style, you can say:

• 状態がいい。

In polite style, you add です:

• 状態がいいです。

Here, です adds politeness. It does not change いい into a noun or act exactly like the English verb to be.

So:

• いい = plain
• いいです = polite

This is normal for -i adjectives:

• 高い。 → 高いです。
• 面白い。 → 面白いです。
• 状態がいい。 → 状態がいいです。

Because この must come directly before the noun phrase it modifies.

Here the full noun phrase is:

• この中古のカメラ = this used camera

Japanese demonstratives like この / その / あの go before the noun:

• この本 = this book
• その人 = that person
• あの車 = that car

In this sentence, この is attached to the whole phrase 中古のカメラ.

So the order is:

• この
  • 中古のカメラ

not something like:

• 中古のこのカメラ in ordinary neutral phrasing

That alternative can exist in special contexts, but it sounds more marked and usually means something like this camera among the used ones. For a normal sentence, この中古のカメラ is the expected order.

Yes, that can be possible, but it feels a bit different.

• 中古のカメラ is a regular noun phrase: a used camera
• 中古カメラ is more like a compound noun: used camera

You often see compound forms in:

• store signs
• product categories
• ads
• short written labels

For example:

• 中古カメラ販売
• 中古カメラ店

In a full sentence, この中古のカメラ sounds very natural and easy to understand.
この中古カメラ is not impossible, but may sound more label-like or compressed depending on context.

No. Japanese is normally written without spaces.

A normal version would be:

この中古のカメラは状態がいいです。

The spaced version is usually just for learners, to help show word boundaries.

So this:

• この　中古　の　カメラ　は　状態　が　いい　です。

is a teaching format, not standard everyday writing.

Yes.

For example:

• このカメラは中古です。
  = This camera is used/secondhand.

That is different from the original sentence:

• この中古のカメラは状態がいいです。
  = This used camera is in good condition.

So 中古 can work in two ways:

1. Before a noun, with の

   • 中古のカメラ = a used camera

2. As the predicate, with です

   • カメラは中古です = the camera is used

That is a useful pattern to remember for many noun-like modifiers in Japanese.