kono si ni ha kouen ga takusan arimasu.

この is the form you use when you put a noun right after it.

• この市 = this city
• これ = this one / this thing

So これ市 is not correct, because これ cannot directly modify a noun.

Here, 市 is read し.

So the phrase is:

• この市 → このし

In this sentence, 市 means a city / municipality. It is not read いち here.

This is a very common pattern in Japanese:

• 場所 + には + ものが + あります

Here is what each particle is doing:

• に marks the location where something exists
• は marks この市 as the topic

So この市には means something like:

• in this city
• or more literally, as for this city, in it...

Using には often gives a natural topic + location feeling in existence sentences.

Because あります is an existence verb, not an action verb.

• に is used for the place where something exists
• で is used for the place where something happens / is done

Compare:

• 公園があります = There is a park
• 公園で遊びます = Play at the park

So in this sentence, parks are not doing anything; they simply exist in the city. That is why に is correct.

In this kind of existence sentence, が often marks the thing that exists.

Pattern:

• 場所には + ものが + あります

So:

• この市には公園がたくさんあります

means that, within the topic this city, the thing being identified as existing is parks.

If you used 公園は, the nuance would change. It could sound more contrastive, like:

• As for parks, this city has many

That is possible in some contexts, but 公園が is the normal, straightforward choice here.

Japanese nouns usually do not change form for singular vs. plural.

So:

• 公園 can mean park or parks

The word たくさん already tells you that there are many, so no special plural ending is needed.

This is very normal in Japanese.

たくさん means many / a lot.

In this sentence, it modifies the idea of existing:

• 公園がたくさんあります = there are many parks

You can also use たくさん before a noun with の:

• たくさんの公園 = many parks

So these are both natural:

• この市には公園がたくさんあります
• この市にはたくさんの公園があります

The first is very common and natural.

Because parks are inanimate.

Japanese uses:

• あります for inanimate things
• います for animate beings such as people and animals

So:

• 公園があります = correct
• 公園がいます = incorrect

If the sentence were about children in the park, then います would be used.

Yes, but Japanese word order is also somewhat flexible.

The most natural textbook order here is:

• この市には 公園が たくさん あります

This follows a common pattern:

• topic/location → thing that exists → quantity → verb

The most important part is that the verb あります comes at the end.

You may see other orders in real Japanese for emphasis, but this version is the standard and easiest one for learners.

Because the sentence is expressing existence, not simply equating one thing with another.

• です is used in sentences like A is B
• あります is used for there is / there are

So this sentence is not saying:

• This city is many parks

It is saying:

• In this city, parks exist in large numbers

That is why あります is the correct verb.

Those spaces are usually just for learners.

Normal Japanese is normally written without spaces:

• この市には公園がたくさんあります。

Textbooks and beginner materials often add spaces to make it easier to see the parts of the sentence. In real Japanese writing, you should expect to see it without spaces.