Learn Hardcore Malay: Selepas itu, saya semak semula semua nota dengan perlahan. - After that, I review all the notes again slowly.

Selepas itu = after that (specific previous action) – it feels slightly more connected to the previous thing that was mentioned.
Kemudian = then / later – more general; often just means then in a sequence.

In many contexts they can both be used for then in a narrative:

Selepas itu, saya semak semula semua nota…
Kemudian, saya semak semula semua nota…

Both are fine and common.

If itu means that, why do we need it in Selepas itu?

Here itu is not pointing at a physical object like that book, but at a previous time or event.

selepas itu = after that (time/event)
If you only say selepas, it sounds incomplete, like saying after in English without saying after what.

So:

Selepas itu, saya semak… = After that, I checked…
Selepas makan, saya tidur. = After eating, I slept. (Here makan plays the role of itu.)

You normally need something after selepas:

selepas itu
selepas makan
selepas kelas

Selepas on its own is rare in standard sentences.

Is there any difference between selepas and lepas?

Yes, mainly in formality and tone:

selepas – more formal / standard; used in writing, news, formal speech, but also in normal conversation.
lepas – more informal / colloquial; very common in everyday spoken Malay.

So you might often hear:

Lepas tu, saya semak semula semua nota dengan perlahan.

This is basically the spoken equivalent of:

Selepas itu, saya semak semula semua nota dengan perlahan.

Why is there a comma after Selepas itu? Is it required?

The comma helps mark a pause and separates the time phrase from the main clause:

Selepas itu, saya semak semula semua nota dengan perlahan.

In writing, it’s standard and recommended to put a comma after an initial time expression like:

Selepas itu, …
Kemudian, …
Pada masa itu, …

In casual writing (texts, chats), people sometimes drop the comma, but in proper written Malay it’s better to include it.

How do we know this is in the past when there is no word like sudah or telah?

Malay usually does not mark tense with a specific word like English does. It relies on:

Context
Time expressions (like selepas itu, semalam, tadi)

Here, Selepas itu already tells you this is a later point in a narrative, so it naturally feels like past tense in English:

Selepas itu, saya semak semula semua nota…
→ After that, I went through all my notes again…

If you really want to emphasize that it’s completed, you can add:

Selepas itu, saya telah semak semula semua nota…
Selepas itu, saya sudah semak semula semua nota…

But they’re not necessary; the original sentence is perfectly complete.

Why is it saya semak and not saya menyemak? Which one is more correct?

Both are grammatically correct, but they differ in register:

semak – base verb; widely used in spoken Malay and also acceptable in casual or semi-formal writing.
menyemak – meN- verb form; often feels more formal and book-like.

You could say:

Selepas itu, saya semak semula semua nota… (everyday, natural)
Selepas itu, saya menyemak semula semua nota… (a bit more formal)

Both mean I checked / I reviewed.
Many verbs allow this shorter spoken form:

baca / membaca (to read)
tulis / menulis (to write)
semak / menyemak (to check/review)

What exactly does semula add to the meaning of semak?

semak on its own = check / review / go through
semak semula = check again / re-check / review again

So:

saya semak semua nota = I check / I review all the notes.
saya semak semula semua nota = I check all the notes again / once more.

The role of semula is to add the meaning again / anew.
It’s similar to adding re- in English (review, redo), but placed after the verb in Malay.

What’s the difference between semula, lagi, and sekali lagi for again?

All can relate to doing something again, but they’re used slightly differently.

semula – most common with verbs of checking, fixing, arranging
- semak semula – check again
- susun semula – rearrange
- bina semula – rebuild
lagi – means again / more / another depending on context
- buat lagi – do (it) again
- minta lagi – ask again / ask for more
- tengok lagi – watch again
sekali lagi – literally one more time
- Cuba sekali lagi. – Try one more time.
- Ulang sekali lagi. – Repeat once again.

In this sentence, semak semula is very natural; semak lagi is also understandable, but semak semula sounds more standard for reviewing notes again.

Why is it semua nota and not nota semua?

In Malay, words like semua (all) normally come before the noun:

semua nota – all the notes
semua buku – all the books
semua pelajar – all the students

nota semua is not natural here. That order (noun + semua) is only used in a few special cases, often with pronouns or for emphasis, e.g.:

mereka semua – all of them
kita semua – all of us
kami semua – all of us (excluding the listener)

So for notes, you keep semua in front: semua nota.

Do we need a classifier like helai with nota (e.g. semua helai nota)?

Not necessarily. Nota is already a countable item by itself in many contexts, especially as a general set of notes (like what you take in a lecture).

semua nota – all the notes (as a collection)

You would bring in a classifier like helai (sheet of) if you want to emphasize individual sheets:

semua helai nota – all the sheets of notes
tiga helai nota – three sheets of notes

In your sentence, semua nota is completely natural and doesn’t feel incomplete.

What does dengan perlahan literally mean, and how does it work grammatically?

Literally:

dengan = with
perlahan = slow

So dengan perlahan = with slow(ness), but the natural translation is slowly.

This is a common pattern in Malay:

dengan cepat – quickly
dengan hati-hati – carefully
dengan senyap – quietly

It’s how Malay often forms something similar to an adverb (how the action is done) from an adjective or descriptive word.

Can we say just perlahan or perlahan-lahan instead of dengan perlahan?

Yes, both are possible and common:

perlahan – slow / slowly
perlahan-lahan – slowly / very gently (repetition often adds a softer, more gradual feel)

So you might see:

… semak semula semua nota perlahan-lahan.
… semak semula semua nota perlahan.
… semak semula semua nota dengan perlahan.

All three can mean reviewed all the notes slowly.
dengan perlahan and perlahan-lahan are especially common in writing. In speech, perlahan-lahan is very frequent because it sounds expressive.

Why is saya used here? Could we use aku instead?

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

saya – polite, neutral, used with strangers, in formal or semi-formal situations, and is safe almost everywhere.
aku – informal, used with close friends, family, or people of the same age group when there is mutual agreement on informality.

So:

Selepas itu, saya semak semula semua nota… – sounds polite and neutral.
Lepas tu, aku semak semula semua nota… – sounds casual, friendly, spoken style.

In a textbook or neutral written sentence, saya is the default choice.

Can we drop saya and just say Selepas itu, semak semula semua nota dengan perlahan?

You can, but it will sound incomplete or unnatural in most standard contexts.

Malay sometimes allows the subject to be dropped if it is very clear from context, particularly in imperatives or instructions:

Semak semula semua nota dengan perlahan. – (You) review all the notes slowly.
Selepas itu, semak semula semua nota. – After that, (you) review all the notes.

In your original sentence, including saya makes it clear it’s I who did it, and it reads as a normal statement:

Selepas itu, saya semak semula semua nota dengan perlahan.

Without saya, that sentence looks more like an instruction to someone else, especially in written form.

Is the overall word order fixed, or can we move things around like in English?

Malay word order here is quite fixed in its main structure:

[Time] + [Subject] + [Verb] + [Object] + [Manner]

So:

Selepas itu (time)
saya (subject)
semak semula (verb phrase)
semua nota (object)
dengan perlahan (manner)

You can sometimes move the manner phrase a bit, but too much movement can sound odd:

Selepas itu, saya semak semula semua nota dengan perlahan. ✅
Selepas itu, saya dengan perlahan semak semula semua nota. ❌ (sounds unnatural)
Selepas itu, saya semak semula dengan perlahan semua nota. – possible, but less natural than the original.

The original order is the most natural and clear.