Sebelum berangkat ke kantor, saya merapikan alis saya di depan cermin.

Sebelum means before. In this sentence, it introduces a time clause: before leaving for the office.

So:

• Sebelum berangkat ke kantor = Before leaving for the office

It works much like English before + clause/action.

Both are possible.

Indonesian often omits the subject in a subordinate clause when the subject is already clear from context, especially when it is the same as the subject of the main clause.

So these are both natural:

• Sebelum berangkat ke kantor, saya merapikan alis saya...
• Sebelum saya berangkat ke kantor, saya merapikan alis saya...

The shorter version sounds very natural because it is obvious that the person leaving is saya.

Berangkat means to leave, to depart, or to set off, usually for a destination.

In this sentence:

• berangkat ke kantor = leave for the office

It is commonly used for going somewhere, especially as the start of a trip or commute.

Examples:

• Saya berangkat pagi. = I leave in the morning.
• Dia sudah berangkat. = He/She has already left.

This is a very common Indonesian distinction:

• ke = to, showing movement toward a place
• di = in / at / on, showing location

So:

• berangkat ke kantor = leaving to the office
• di depan cermin = in front of the mirror

A simple way to remember it:

• ke answers where to?
• di answers where?

Rapi is an adjective meaning neat or tidy.

Merapikan is a verb built from rapi, and it means to make neat, to tidy up, or to groom/straighten.

So:

• rapi = neat
• merapikan = to neaten / tidy / groom

In this sentence, merapikan alis saya means something like tidying/grooming my eyebrows.

This is part of a very common Indonesian verb pattern. The prefix meN- often forms active verbs.

Here, the base is rapi, and with affixes it becomes merapikan.

You do not need to analyze every detail at first, but it helps to know that:

• meN- often marks an active verb
• -kan often gives the sense of making something become a certain way, or doing something to an object

So merapikan alis is literally something like make the eyebrows neat.

By itself, alis can refer to eyebrow or eyebrows, depending on context.

Indonesian nouns usually do not have to show singular vs. plural the way English does. So:

• alis saya can naturally mean my eyebrows

Because people normally groom both eyebrows, that is the most natural interpretation here.

If someone really wanted to emphasize plurality, context would usually do that rather than changing the noun.

Because Indonesian usually states possession directly with the noun.

So:

• saya merapikan alis saya = I tidy my eyebrows

Even though the subject is already saya, the possessor of alis is still clearly marked with another saya.

This is very normal in Indonesian. English also does something similar:

• I tidy my eyebrows

You do not say I tidy eyebrows if you specifically mean your own.

Literally, it means at the front of the mirror or more naturally in front of the mirror.

Breakdown:

• di = at/in
• depan = front
• cermin = mirror

So:

• di depan cermin = in front of the mirror

This is a very common expression:

• di depan rumah = in front of the house
• di depan kelas = at the front of the classroom

Indonesian does not use articles like the and a/an the way English does.

So:

• ke kantor can mean to the office
• cermin can mean the mirror or a mirror

The exact meaning depends on context.

In this sentence, English naturally uses the office and the mirror, but Indonesian does not need separate article words.

Yes. Indonesian word order is somewhat flexible, especially with time expressions.

For example, this is also natural:

• Saya merapikan alis saya di depan cermin sebelum berangkat ke kantor.

This means the same thing. The difference is mainly focus:

• Sebelum berangkat ke kantor, ... puts the time frame first
• Saya merapikan... sebelum berangkat ke kantor starts with the main action first

Both are good Indonesian.

Yes, it is natural and neutral.

It sounds like standard everyday Indonesian. The use of saya makes it a bit more neutral or polite than aku.

For example:

• Sebelum berangkat ke kantor, saya merapikan alis saya di depan cermin.
  neutral / standard

A more casual version might be:

• Sebelum berangkat ke kantor, aku merapikan alisku di depan cermin.

Both are natural, but saya is more formal than aku.