tosyokan ha kuzi ni simarimasu.

When は is used as the topic particle, it is pronounced wa, not ha.

So in this sentence:

• 図書館は = toshokan wa

This is a special rule for the particle は.
If は appears as part of a normal word, it is usually pronounced ha.

は marks the topic of the sentence: what the sentence is about.

So 図書館は means something like:

• As for the library...
• The library...

In natural English, we often just translate it as the library, but the Japanese nuance is more like introducing the topic.

Here, に marks a specific point in time.

• 九時に = at nine o’clock

Japanese often uses に with exact times such as:

• 三時に = at 3 o’clock
• 月曜日に = on Monday
• 七月四日に = on July 4th

So in this sentence, に tells you the exact time when the action happens.

九時 is read くじ (kuji), meaning nine o’clock.

Breakdown:

• 九 = く / きゅう for nine
• 時 = じ for o’clock

With hours, there are some special readings, so it is worth memorizing them. For example:

• 一時 = いちじ
• 四時 = よじ
• 七時 = しちじ
• 九時 = くじ

閉まります is the polite non-past form of the verb 閉まる.

• Dictionary form: 閉まる
• Polite form: 閉まります

The non-past form in Japanese can mean:

• present habitual: closes
• future: will close

In this sentence, it usually means closes / will close, depending on context.

Because 閉まる and 閉める are different verbs.

• 閉まる = to close / to be closed
  
  • intransitive
• 閉める = to close something
  
  • transitive

In this sentence, the library is the thing that closes, so Japanese uses the intransitive verb:

• 図書館は九時に閉まります。 = The library closes at nine.

If a person closes something, you would use 閉めます:

• 係員がドアを閉めます。 = The staff member closes the door.

Japanese often leaves out subjects when they are obvious from context.

In English, you might say:

• It closes at nine.
• The library closes at nine.

In Japanese, once the topic is given with 図書館は, there is no need to add a separate word for it. Japanese frequently relies on context instead of explicitly stating every subject or pronoun.

Yes, 図書館が九時に閉まります is possible, but the nuance changes.

• 図書館は九時に閉まります
  = speaking generally about the library as the topic
• 図書館が九時に閉まります
  = puts more focus on the library as the thing that closes

Very roughly:

• は = topic / contrast / general statement
• が = subject focus / identifying what does the action

In many beginner situations, は is the more natural choice for a simple statement like this.

Sometimes, but with a specific clock time like 九時, に is normally used.

So:

• 九時に閉まります = natural and standard

Japanese often omits に with more relative time words, such as:

• 今日 = today
• 明日 = tomorrow
• 毎日 = every day

For example:

• 明日閉まります can be fine.

But with an exact time like nine o’clock, learners should usually include に.

No. Normal Japanese is usually written without spaces.

So this sentence would normally appear as:

• 図書館は九時に閉まります。

Spaces are often added in beginner materials to make the sentence easier to read and to show where words or particles are.

It can be either, depending on context.

Because 閉まります is a non-past form, it can mean:

• a habitual fact: The library closes at nine.
• a future event: The library will close at nine.

For example:

• On a sign about business hours, it probably means a regular fact.
• In a conversation about today’s schedule, it might mean tonight’s closing time.

Japanese often lets context decide which meaning is intended.