zikan ga dekitara, tosyokan de nihongo wo benkyousimasu.

In 時間ができたら, the verb is できる, and the thing that comes into being / becomes available is marked by が.

So the idea is:

• 時間ができる = time becomes available
• natural English meaning: to have time / to be free

That is why it is 時間が, not 時間を.

A very literal breakdown is:

• 時間 = time
• が = marks what appears/becomes available
• できたら = if/when it becomes available

So 時間ができたら means if/when I have time.

できたら is the -たら conditional form of できる.

• dictionary form: できる
• past form: できた
• conditional: できたら = if/when it happens

So:

• 時間ができる = time becomes available
• 時間ができたら = if/when time becomes available

In natural English, this usually becomes:

• If I have time, ...
• When I have time, ...

depending on context.

The -たら form often covers both ideas in Japanese. The difference usually depends on context.

In this sentence:

• 時間ができたら、図書館で日本語を勉強します。

it can mean either:

• If I have time, I’ll study Japanese at the library.
• When I have time, I’ll study Japanese at the library.

If the speaker is not sure whether free time will happen, English often uses if.
If the speaker expects it more naturally, English may use when.

Japanese leaves that a bit more open.

Both are possible, but the nuance is slightly different.

• 時間があったら = if/when there is time
• 時間ができたら = if/when time becomes available / if I manage to have time

できる often suggests that time opens up, appears, or becomes free. It can feel a little more like once I find some time.

So:

• 時間があったら sounds a bit simpler and more neutral
• 時間ができたら can sound like the speaker is busy, and free time may become available later

Both are natural.

で marks the place where an action happens.

Since studying is an action, the location is marked with で:

• 図書館で勉強します = study at the library

Compare:

• 図書館に行きます = go to the library
  (に marks destination)
• 図書館で勉強します = study at the library
  (で marks location of action)

So here, で is correct because the action 勉強します happens there.

を marks the direct object of the verb.

In this sentence:

• 日本語を勉強します = study Japanese

The thing being studied is 日本語, so it takes を.

This is the normal pattern:

• 数学を勉強します = study math
• 歴史を勉強します = study history
• 日本語を勉強します = study Japanese

勉強します is the polite form of 勉強する.

• 勉強する = plain form
• 勉強します = polite form

Japanese often uses the polite form in neutral conversation, class examples, and everyday polite speech.

So this sentence is simply in polite style:

• 時間ができたら、図書館で日本語を勉強します。

A plain-style version would be:

• 時間ができたら、図書館で日本語を勉強する。

Yes, the subject is omitted, which is very common in Japanese.

English usually needs a subject like I, but Japanese often leaves it out when it is obvious from context.

So this sentence naturally implies something like:

• (私は) 時間ができたら、図書館で日本語を勉強します。

In English, that would be:

• If/when I have time, I study/will study Japanese at the library.

The subject is usually understood from the situation.

In Japanese, the non-past form often covers both:

• present
• future

So 勉強します can mean:

• I study
• I will study

Here, because of 時間ができたら (if/when I have time), the sentence clearly refers to a future or habitual action:

• If I have time, I’ll study Japanese at the library.
• When I have time, I study Japanese at the library.

Japanese does not need a special future tense the way English often does.

The structure is:

• 時間ができたら = if/when I have time
• 図書館で = at the library
• 日本語を = Japanese
• 勉強します = study

So the full pattern is:

[Condition] + [Place] + [Object] + [Verb]

Japanese verbs usually come at the end of the sentence.

Yes, Japanese word order is more flexible than English, as long as the particles stay correct.

For example, these are all understandable:

• 時間ができたら、図書館で日本語を勉強します。
• 時間ができたら、日本語を図書館で勉強します。

Both mean basically the same thing.

However, the most natural order usually keeps related information grouped nicely, and the original sentence sounds very normal.

The most important thing is not word order by itself, but the particles:

• 時間が
• 図書館で
• 日本語を

No, it is not strictly necessary, but it is very common and helpful.

The comma shows a pause after the conditional phrase:

• 時間ができたら、図書館で日本語を勉強します。

It makes the sentence easier to read:

• If/when I have time, ...
• then the main statement follows

In Japanese, commas are often used for clarity and rhythm, not only by strict grammar rules.

No, standard Japanese normally does not use spaces like this.

A normal written version would be:

時間ができたら、図書館で日本語を勉強します。

Spaces are often added in textbooks or beginner materials to help learners see the parts more clearly.

So the spaced version is for learning, not standard native writing.

Here, 時間 means time available / free time, not a specific clock time like 3 o’clock.

Because it is used with できる, the phrase 時間ができる means:

• to have time
• to get some free time
• for time to become available

So in this sentence, 時間 is about having time for something, not about telling time.