Learn Hardcore Indonesian: Saya berenang di kolam renang sebelum sarapan. - I swim in the swimming pool before breakfast.

di is the Indonesian preposition for “in/at.” When you specify the location of an action, you add di before the place noun. So di kolam renang means “in the swimming pool.” Without di, it would sound ungrammatical: you can’t say berenang kolam renang on its own.

Why is kolam renang two separate words instead of one?

kolam renang is a compound noun made of kolam (“pool/pond”) + renang (“swim”). The first word names the container or place, and the second word names its function. Many Indonesian compounds work like this (e.g. rumah sakit = “house of sickness” = “hospital”).

How can we tell if this sentence is talking about a past event or a habitual action?

Indonesian verbs don’t change form for tense. You infer time from context or use time/aspect markers. Here, sebelum sarapan (“before breakfast”) suggests a routine.

For a past emphasis, add sudah or telah:
Saya sudah berenang di kolam renang sebelum sarapan. (“I swam in the pool before breakfast.”)
For a habitual routine, you can add biasanya:
Biasanya saya berenang di kolam renang sebelum sarapan. (“Usually I swim in the pool before breakfast.”)

Could we place sebelum sarapan at the beginning of the sentence?

Yes. Time expressions are flexible in Indonesian. You can say:
Sebelum sarapan, saya berenang di kolam renang.
It still means “Before breakfast, I swim in the pool.”

Why do we use saya instead of aku, or can we omit the pronoun altogether?

saya is the formal/polite pronoun for “I.” aku is informal and used among friends or close family. You can also drop the subject pronoun if context is clear:
Berenang di kolam renang sebelum sarapan.
But including saya makes the subject explicit.

What does sebelum mean exactly? Can you use it with any noun?

sebelum means “before” in a temporal sense. It must be followed by a time-related word or phrase, such as sebelum tidur (“before sleeping”), sebelum makan (“before eating”), or sebelum berangkat (“before leaving”). It doesn’t pair with nouns that aren’t time references.

Is there any difference between sarapan and makan pagi?

Both mean “breakfast.”

sarapan is a single word (loaned via Malay) that can be a noun (“breakfast”) or verb (“to have breakfast”).
makan pagi literally means “eat morning.”
They’re interchangeable in most contexts, though sarapan is more commonly used for the meal itself.

Why not just say kolam instead of kolam renang?

While kolam alone means any kind of pool or pond (e.g., fish pond), kolam renang specifies that it’s a swimming pool. Using the full compound removes ambiguity when you’re talking about swimming.