gogo ni jikan ga dekitara, toshokan ni yorimasu.

If I have time in the afternoon, I will stop by the library.

Breakdown of gogo ni jikan ga dekitara, toshokan ni yorimasu.

• に: destination particle
• が: subject particle
• に: time particle
• 時間じかん: time

Questions & Answers about gogo ni jikan ga dekitara, toshokan ni yorimasu.

Why does 時間ができたら use できる? Isn’t that verb usually to be able to or to be made?

In this sentence, できる means to come into existence / to become available.

So 時間ができたら literally means:

• if time becomes available
• if some free time opens up

This is very natural Japanese. With 時間, できる often means to get free time.

Compare:

• 時間ができたら = if I end up having some free time / if time opens up
• 時間があったら = if I have time

The first one often suggests that the speaker is currently busy, but free time might appear later.

Why is it 時間が and not 時間を?

Because できる is an intransitive verb here.

The thing that comes into existence or becomes available is marked with が:

• 時間ができる = time becomes available
• 予定ができる = a plan gets made / a schedule is set
• 用事ができる = something comes up

If you used を, it would suggest a direct object, but できる does not work that way in this meaning.

A useful comparison:

• 時間ができたら = if free time opens up
• 時間を作れたら = if I can make time

Both can be natural, but they are slightly different in nuance.

How does 〜たら work in できたら?