Teman perempuan saya pindah ke kos baru pada Juli karena kuliahnya dimulai lagi.

In Indonesian, possessors usually come after the noun.

• teman saya = my friend
• rumah saya = my house

So teman perempuan saya follows the normal Indonesian pattern. Literally, the order is something like friend female my, but the natural English order is my female friend.

Usually it means female friend.

If you want to say girlfriend in the romantic sense, Indonesian more commonly uses pacar saya.

That said, context matters. In some situations, teman perempuan could sound slightly ambiguous, but the safest default understanding is female friend, not romantic partner.

Both perempuan and wanita relate to female/woman, but they are not always interchangeable in tone.

• teman perempuan = female friend
• teman wanita is possible, but can sound more formal, a bit old-fashioned, or sometimes like lady friend

So in this sentence, perempuan is a very natural choice.

Kos refers to a rented room or boarding place, often used by students or young workers.

It is short for indekos. Depending on context, it can mean:

• a room in a boarding house
• student accommodation
• a small rented place, often with shared facilities

So kos is not exactly the same as apartment or dorm, though it can overlap somewhat in meaning.

Because adjectives usually come after the noun in Indonesian.

• kos baru = new boarding place
• rumah besar = big house
• buku bagus = good book

This is one of the basic word-order differences from English.

Ke marks movement toward a place, so it often means to.

• pindah ke kos baru = move to a new boarding place
• pergi ke kampus = go to campus

Here, pindah means move, and ke shows the destination.

Also, Indonesian does not require articles like a or the, so ke kos baru can mean to a new boarding place or to the new boarding place, depending on context.

Pada is a standard preposition for time expressions, especially in more careful or formal Indonesian.

So:

• pada Juli = in July
• pada hari Senin = on Monday

Meanwhile, di is mainly a place preposition, though in casual speech some people do use di with time expressions, especially in phrases like di bulan Juli.

So pada Juli sounds standard and correct here.

Also, Juli is capitalized because month names are capitalized in Indonesian.

Kuliah is related to university study. Depending on context, it can refer to:

• college/university classes
• lectures
• one’s university studies

The ending -nya here most naturally means her, referring back to teman perempuan saya.

So kuliahnya means something like:

• her classes
• her university studies
• her college term/coursework, depending on context

In this sentence, the most natural idea is that her classes started again.

Dimulai is a passive form built with di-.

• mulai = start / begin
• dimulai = be started / be begun

Indonesian often uses the passive when the doer is not important or not mentioned. Here, the focus is on the fact that the classes resumed, not on who started them.

So kuliahnya dimulai lagi is naturally understood as her classes started again or her classes resumed.

In everyday speech, you may also hear kuliahnya mulai lagi, which is a little simpler and very common.

Here lagi means again.

So dimulai lagi means started again or resumed.

It suggests that there was a break before this, such as:

• a semester break
• a holiday
• a pause in classes

So lagi adds the idea of something happening once more after stopping.

Yes. Indonesian allows that.

You could also say:

Karena kuliahnya dimulai lagi, teman perempuan saya pindah ke kos baru pada Juli.

That still means the same basic thing. The difference is mainly emphasis:

• Teman perempuan saya pindah ... karena ...
  starts with the main event, then gives the reason
• Karena ... , teman perempuan saya pindah ...
  starts with the reason first

Both are natural.

Pindah is the normal, everyday word here.

• Saya pindah rumah. = I’m moving house.
• Dia pindah ke kos baru. = She moved to a new boarding place.

Berpindah also exists, but it sounds more formal and is less common in ordinary conversation for this kind of situation.

So pindah ke kos baru is exactly what you would expect in natural Indonesian.