Learn Hardcore Malay: Saya berjalan perlahan di dalam rumah.

Malay does not use a separate verb like “am/is/are” before other verbs.
The verb berjalan already means “to walk / to be walking”, so Saya berjalan covers “I walk”, “I am walking”, or even “I walked”, depending on context.
Malay verbs generally don’t change their form for tense (past, present, future), and they don’t need helping verbs like “am” or “do”.
If you really want to stress the “in the middle of doing it” feeling (English present continuous), you can add sedang:

Saya sedang berjalan perlahan di dalam rumah. = I am (currently) walking slowly inside the house.

What does the prefix ber- in berjalan do? Why not just use jalan?

The root jalan means “road/street” and also “to walk / to go”.
The prefix ber- turns it into an intransitive verb: berjalan = “to walk / to go (by walking) / to move along”.
So berjalan literally feels like “to be in the state of walking / going”.
You will see ber- attached to many roots to form verbs, for example:

berlari (lari = run) → to run
bermain (main = play) → to play

Can I say “Saya jalan perlahan di dalam rumah” instead of “Saya berjalan perlahan…”?

Yes, in casual spoken Malay many people say jalan as a verb without ber-, especially in informal conversation:

Saya jalan perlahan dalam rumah.
This sounds informal/colloquial, and sometimes a bit “childish” in careful writing.
For standard, neutral Malay (in writing or polite speech), Saya berjalan perlahan di dalam rumah is preferred.

Is perlahan an adjective (“slow”) or an adverb (“slowly”)?

Malay usually uses the same word for both an adjective and an adverb.
So perlahan can mean “slow” or “slowly”, depending on what it’s describing:

kereta yang perlahan = a slow car (adjective)
berjalan perlahan = to walk slowly (adverbial use)
English needs slow vs slowly, but Malay just uses perlahan in both roles.

What’s the difference between perlahan and perlahan-lahan?

Perlahan-lahan is a reduplicated form that often adds a feeling of “very slowly / slowly and carefully / gradually”.

Saya berjalan perlahan di dalam rumah. = I walk slowly in the house.
Saya berjalan perlahan-lahan di dalam rumah. = I walk very slowly / I move slowly and carefully in the house.
Both are correct; perlahan-lahan is simply more emphatic or descriptive.

Could this sentence also mean “I am walking quietly in the house”? Does perlahan also mean “quietly”?

Yes, perlahan can also carry the idea of “softly/quietly” when it describes sounds or actions that can be “soft”:

cakap perlahan = speak softly / quietly
In Saya berjalan perlahan di dalam rumah, it mainly means “slowly”, but the nuance can also include “quietly, carefully”, especially from context.
If you want to emphasise secrecy or silence, you might choose words like senyap-senyap (very quietly/secretly) or diam-diam.

Why is it di dalam rumah instead of just di rumah or just dalam rumah? What’s the difference?

All three are possible, but they have slightly different nuances:

di rumah = at the house / at home
- Focus: location at that place, not necessarily emphasising “inside”.
dalam rumah = inside the house
di dalam rumah = also inside the house; often a bit more explicit or formal.

In your sentence, di dalam rumah emphasises being inside the house, not outside or just “at” the house.
In everyday speech, dalam rumah and di dalam rumah are both very common and usually interchangeable.

Is di dalam one word or two? I’ve seen di sometimes attached to words.

In this sentence, di dalam is two separate words:

di = preposition “at / in / on”
dalam = “inside / inner part / in”

You only attach di- to a word when it forms a passive verb prefix, like:

diambil (ambil = take) → was taken
dibuat (buat = make) → was made

As a preposition meaning “at/in/on”, di must be written separately:

di rumah, di sekolah, di dalam rumah

Why is there no word for “the” in rumah? How do I say “the house” versus “a house” in Malay?

Malay normally doesn’t use articles like “a” or “the”.
The bare noun rumah can mean “a house”, “the house”, or just “house/home”, depending on context.

To be more specific, Malay uses other words:

rumah itu = that house / the house (already known in context)
rumah ini = this house
sebuah rumah = a house / one house (using the classifier sebuah)

So di dalam rumah can be understood as “inside the house” if the context already makes the house specific.

How do I change this sentence to mean “I walked slowly inside the house” or “I will walk slowly inside the house”?

The verb berjalan itself doesn’t change. You show past or future mainly with time words or particles:

Past:
- Tadi saya berjalan perlahan di dalam rumah. = I walked slowly inside the house just now.
- Saya sudah berjalan perlahan di dalam rumah. = I have already walked slowly inside the house.
Future:
- Nanti saya akan berjalan perlahan di dalam rumah. = I will walk slowly inside the house later.
- Esok saya akan berjalan perlahan di dalam rumah. = Tomorrow I will walk slowly inside the house.

Context usually makes the time clear, so often people just say the original sentence with an appropriate time word nearby.

Can I move perlahan to another place, like “Saya perlahan berjalan di dalam rumah” or “Saya berjalan di dalam rumah perlahan”?

The most natural word order is:
Saya (subject) + berjalan (verb) + perlahan (adverb) + di dalam rumah (place).

Other orders are possible but can sound unusual or need special emphasis:

Saya perlahan berjalan di dalam rumah. → sounds poetic or marked, like focusing on me being slow as I walk.
Saya berjalan di dalam rumah perlahan. → possible, but less natural in everyday speech.

For normal sentences, keep perlahan directly after berjalan.

Is the subject pronoun Saya necessary? What happens if I just say “Berjalan perlahan di dalam rumah.”?

If you drop Saya, the sentence is no longer clearly “I walk…”.
Berjalan perlahan di dalam rumah is more likely to be understood as:

an instruction/command: Walk slowly inside the house.
or a fragment in a longer description, like a note or caption.

To clearly say “I walk / I am walking…”, include Saya, unless the subject is extremely clear from previous context and you are writing in a very telegraphic style.

What is the difference between saya and aku here? Could I say “Aku berjalan perlahan di dalam rumah”?

Yes, you can say Aku berjalan perlahan di dalam rumah. The difference is formality and relationship:

saya: polite, neutral; used with strangers, older people, in formal situations, or generally safe in almost any context.
aku: informal/intimate; used with close friends, family, or when speaking casually with someone of lower or similar status.

The meaning of the sentence doesn’t change; only the tone and social level change.

How do you pronounce each word in “Saya berjalan perlahan di dalam rumah”?

Approximate pronunciation (slashes = IPA-like):

Saya → /sa-ya/
berjalan → /bər-ja-lan/ (the r is a single tap; e in ber- is like the a in sofa)
perlahan → /pər-la-han/ (final h is pronounced lightly)
di → /di/
dalam → /da-lam/
rumah → /ru-mah/ (again, final h is audible)

Malay stress is relatively even, often a bit stronger on the second-to-last syllable, but not as strong as English stress.