Karena loker di gym penuh, saya membawa ransel saya ke ruang tunggu.

Karena means because. It introduces the reason:

• Karena loker di gym penuh = Because the lockers at the gym were full

In Indonesian, a karena clause can come either before or after the main clause:

• Karena loker di gym penuh, saya membawa ransel saya ke ruang tunggu.
• Saya membawa ransel saya ke ruang tunggu karena loker di gym penuh.

Both are natural.

The comma separates the reason clause from the main clause because the sentence begins with the subordinate clause:

• Karena loker di gym penuh, ...

This is similar to English:

• Because the lockers were full, I took my backpack to the waiting room.

If the karena clause comes second, the comma is often omitted:

• Saya membawa ransel saya ke ruang tunggu karena loker di gym penuh.

Loker means locker. It is a borrowed word, adapted from English/Dutch usage. In everyday Indonesian, it is very common.

Be aware that loker can also mean job vacancy in some contexts, especially online ads, but here it clearly means locker because of di gym and penuh.

Di is a preposition meaning in / at / on, depending on context. Here:

• di gym = at the gym

So loker di gym means the lockers at the gym.

A useful thing to remember:

• di as a preposition is written separately: di gym, di rumah, di ruang tunggu
• di- as a prefix for passive verbs is written together: dibawa, ditutup

In modern Indonesian, gym is commonly used, especially in urban or casual contexts. You may also see:

• pusat kebugaran = fitness center
• tempat gym = gym place, less formal/casual phrasing

Using gym is very natural in everyday speech.

Penuh means full.

So:

• loker di gym penuh = the lockers at the gym were full

Indonesian does not need a verb like were in this kind of sentence. It is normal to say simply:

• Kamarnya penuh = The room is full
• Busnya penuh = The bus is full

Indonesian often leaves out the verb to be in simple descriptions.

English:

• The lockers were full

Indonesian:

• Loker di gym penuh

There is no separate word for were here. This is completely normal. Indonesian often goes straight from the noun to the adjective.

Membawa is the standard verb form meaning to carry / to bring / to take.

The base/root is bawa.
With the meN- prefix, it becomes membawa, which is the normal active verb in standard Indonesian.

Compare:

• Saya membawa ransel saya = I carried/brought my backpack
• Saya bawa ransel saya = also common in casual speech, but less formal/less standard

So membawa is the more complete and standard form.

It can mean any of those, depending on context.

• bring if the focus is movement toward a place
• take if the focus is moving something somewhere
• carry if the physical carrying is emphasized

In this sentence, English might naturally say:

• I took my backpack to the waiting room or
• I brought my backpack to the waiting room

Indonesian membawa covers all of these possibilities.

Ransel saya means my backpack.

Indonesian often includes possessive words clearly when needed:

• ransel saya = my backpack
• tas saya = my bag

Could you say just ransel? Sometimes yes, if ownership is obvious from context. But ransel saya is clearer and very natural.

The first saya is the subject:

• saya membawa = I carried/took

The second saya shows possession:

• ransel saya = my backpack

So they have different jobs:

• saya = I
• saya after a noun = my

This repetition is normal in Indonesian.

Yes. You could say:

• Karena loker di gym penuh, saya membawa ranselku ke ruang tunggu.

Both ransel saya and ranselku mean my backpack.

The difference is mostly style:

• ransel saya sounds a bit more neutral or formal
• ranselku can sound slightly more personal, closer, or more conversational

Both are correct.

Ke is a preposition meaning to when showing movement toward a place.

• ke ruang tunggu = to the waiting room

Compare:

• di ruang tunggu = in/at the waiting room
• ke ruang tunggu = to the waiting room

So:

• di = location
• ke = direction/movement toward

Ruang tunggu literally means waiting room.

It is made up of:

• ruang = room/space
• tunggu = wait

So literally it is something like waiting space/room, but the natural English translation is waiting room.

Yes, it is very normal.

The structure is:

• Karena loker di gym penuh = reason clause
• saya membawa ransel saya ke ruang tunggu = main clause

Inside the main clause, the order is also standard:

• saya = subject
• membawa = verb
• ransel saya = object
• ke ruang tunggu = destination

So it follows a common Indonesian pattern: Subject + Verb + Object + Place/Destination

Yes, in more casual speech:

• Karena loker di gym penuh, aku membawa ranselku ke ruang tunggu.

Difference:

• saya = more neutral, polite, standard
• aku = more casual, personal

Both are correct, but saya is safer in general and more appropriate for standard written Indonesian.

You could say things like:

• loker di gym penuh
• semua loker di gym penuh = all the lockers at the gym were full

But penuh semua is less natural in this exact sentence unless you are emphasizing that every single one was full. The original sentence is already natural and clear.

A very natural alternative is:

• Karena semua loker di gym penuh, saya membawa ransel saya ke ruang tunggu.

It is mostly neutral standard Indonesian.

Why:

• karena is standard
• saya is polite/neutral
• membawa is the standard verb form
• gym is modern everyday vocabulary

So the sentence sounds natural in normal writing or speech. It is not extremely formal, but it is not slangy either.