Learn Hardcore Indonesian: Anjing saya hampir saja mengejar kucing tetangga di halaman. - My dog almost chased the neighbor's cat in the yard.

So saya anjing would literally read I dog, which is ungrammatical (or at best sounds like I am a dog, but even that would normally be saya anjing only in very special contexts, and more naturally saya adalah anjing).

What is the difference between saya and aku here? Could I say anjing aku?

Both saya and aku mean I / me, but they differ in formality:

saya – more formal, polite, neutral; safe in almost all situations
aku – informal, used with friends, family, and in casual speech

In possessive form:

anjing saya – neutral / polite my dog
anjing aku – informal my dog

Grammatically, anjing aku is possible, but anjing saya is more standard and slightly more formal.

Can I also say anjingku instead of anjing saya? Is there any difference?

Yes, you can:

anjing saya = my dog
anjingku = my dog

-ku is a clitic attached to the noun and is informal / neutral, often used in speech and writing (including literature, songs).

Nuance:

anjing saya sounds a bit more neutral/formal, especially in writing.
anjingku sounds more personal and slightly more informal or expressive.

All three are correct: anjing saya, anjing aku, anjingku (with different levels of formality / style).

What exactly does hampir mean, and what extra nuance does hampir saja add?

hampir means almost / nearly.

Anjing saya hampir mengejar kucing…
→ My dog almost chased the cat…

hampir saja adds emphasis, often with a feeling of relief or a narrow escape:

Anjing saya hampir saja mengejar kucing tetangga…
→ My dog almost chased the neighbor’s cat (and I’m implying it just didn’t happen, or it was very close).

So hampir saja is like almost (did!) / so nearly in English, more expressive than plain hampir.

With hampir saja mengejar, did the dog actually chase the cat or not?

Normally, with hampir (or hampir saja) + verb, the action did not actually happen:

Anjing saya hampir saja mengejar kucing tetangga…
→ The dog did not end up chasing it; it was very close to doing so.

If it really did chase the cat, you would normally say:

Anjing saya mengejar kucing tetangga… (no hampir)

Indonesian has no tense endings. How do we know this sentence is about the past and not the future?

On its own, the sentence is time-neutral. It could mean:

past: My dog almost chased the neighbor’s cat (earlier).
future: My dog almost chased the neighbor’s cat (just now / was about to).

In real usage, context or time words make it clear:

Tadi anjing saya hampir saja mengejar kucing tetangga di halaman.
→ Earlier, my dog almost chased… (past)
Tadi pagi, kemarin, nanti, sebentar lagi, etc., specify time.
Without such words, Indonesian relies on context, not verb tense.

What does mengejar consist of, and how is it related to kejar?

The base (root) verb is kejar = to chase.

When you add the me- prefix, you get an active transitive verb:

me-
- kejar → mengejar

The me- prefix changes form depending on the first consonant of the root (me-, mem-, men-, meng-, meny-, menge-, etc.). For kejar, it surfaces as mengejar.

Functionally:

kejar – dictionary / root form
mengejar – to chase (something) in a normal sentence:
- Anjing saya mengejar kucing. = My dog chases / chased the cat.

Why is it kucing tetangga and not something like kucingnya tetangga or kucing tetangga saya?

kucing tetangga literally is neighbor cat, but in practice it means the neighbor’s cat. The possession is understood from context.

Some variations:

kucing tetangga – neighbor’s cat (whose neighbor is clear from context; maybe the only relevant neighbor).
kucing tetangga saya – my neighbor’s cat, explicitly saying the neighbor is my neighbor.
kucing tetangga sebelah – the next-door neighbor’s cat.

You only add saya, sebelah, etc., if you need to be more specific. In everyday speech, kucing tetangga is often enough.

How do I say my neighbor’s cat more explicitly?

The most explicit and common form is:

kucing tetangga saya – literally cat neighbor I, i.e. my neighbor’s cat.

So you could say:

Anjing saya hampir saja mengejar kucing tetangga saya di halaman.
→ My dog almost chased my neighbor’s cat in the yard.

What exactly does di halaman mean? Is halaman like yard, garden, or something else?

di = in / at / on (location preposition).
halaman = generally yard, courtyard, or the area around a house (front yard, backyard).

So di halaman is in the yard / in the yard area. The exact English word (yard, garden, courtyard) depends on the house type and context.

What is the difference between di halaman and ke halaman?

di halaman – in/at the yard, static location.
- Anjing saya bermain di halaman. = My dog is playing in the yard.
ke halaman – to the yard, movement towards.
- Anjing saya lari ke halaman. = My dog ran to the yard.

In the original sentence, di halaman is used because the action happens in that place, not towards it.

Can I move hampir saja to another position, like Anjing saya hampir saja mengejar… vs Anjing saya mengejar hampir saja…?

Natural positions:

Anjing saya hampir saja mengejar kucing tetangga di halaman.
Anjing saya hampir mengejar kucing tetangga di halaman.

Both are fine and common.

But Anjing saya mengejar hampir saja kucing tetangga… is wrong or very unnatural; hampir (saja) normally comes before the verb it modifies.

Does tetangga mean a specific neighbor here, or neighbors in general?

tetangga by itself just means neighbor.

In kucing tetangga, context usually makes it a specific neighbor’s cat (the one everyone knows about). However, grammatically it could mean a/the neighbor’s cat, without specifying which neighbor.

If you want to be very specific, you add more information:

kucing tetangga saya – my neighbor’s cat
kucing tetangga sebelah – next-door neighbor’s cat
kucing tetangga depan – neighbor across the street’s cat, etc.