Learn Hardcore Indonesian: Dia memakai kacamata pelindung dan sarung tangan karet saat melakukan eksperimen. - He/She wears protective goggles and rubber gloves when doing an experiment.

Dia is a gender‑neutral third‑person singular pronoun in Indonesian. It can mean “he” or “she”, and the gender is understood only from context (or not specified at all).

It does not mean “they” – the plural “they” is mereka.
It is usually used only for people; for things, Indonesians normally use itu or just omit the pronoun.

So in this sentence, dia = “he/she (one person)”, with no gender information in the word itself.

What’s the difference between memakai, pakai, and menggunakan? Could we replace memakai in this sentence?

All three are related to the idea of using, but the nuances differ.

pakai = the base verb “to use / to wear”. Common in casual speech.
memakai = meN-
- pakai → a more “complete” active form. It often means “to wear (on the body)” or “to use” something physically.
menggunakan = “to use” in a bit more formal/neutral sense, not focused on wearing; appropriate for tools, methods, systems, etc.

In this sentence:

Dia memakai kacamata pelindung dan sarung tangan karet …
is the most natural, because these are items worn on the body.

You could also say:

Dia menggunakan kacamata pelindung dan sarung tangan karet …

That is still correct, just slightly more formal/neutral and a little less “wearing‑focused”.
Using just pakai (without meN-): Dia pakai kacamata… is also common in everyday, informal speech.

There’s no tense marking in memakai or melakukan. How do we know if the sentence is present, past, or future?

Indonesian verbs generally don’t change form for tense. The verb forms memakai and melakukan can cover:

present: “He/she wears / is wearing …”
past: “He/she wore / was wearing …”
habitual: “He/she (always) wears … when doing experiments.”

Time is usually shown with time words, not verb changes, e.g.:

tadi – earlier
kemarin – yesterday
akan – will
sudah / telah – already
sedang – in the middle of (doing something, in progress)

Examples:

Tadi dia memakai kacamata pelindung … = He/she was wearing earlier.
Besok dia akan memakai kacamata pelindung … = He/she will wear tomorrow.

Without such markers, you understand the tense from context.

What does saat mean here, and how is it different from ketika or waktu?

In saat melakukan eksperimen, saat means “when / while / at the time (of)”.

It is very close in meaning to:

ketika – when
waktu – when / the time (that)

In this sentence you could also say:

ketika melakukan eksperimen
waktu melakukan eksperimen

All three sound natural. Roughly:

saat is slightly bookish but very common and neutral.
ketika is also neutral and a bit literary/formal.
waktu is common in everyday speech but still perfectly standard.

So saat melakukan eksperimen ≈ “when (he/she is) doing experiments / during experiments”.

Why does the sentence use melakukan eksperimen instead of bereksperimen? Are both correct?

Both are grammatical, but the structure and nuance differ:

melakukan eksperimen
- melakukan = “to do / to carry out”.
- eksperimen = the object (“an experiment”).
- Literally: “to do an experiment / conduct an experiment.”
- Slightly more formal or technical, like English “conduct an experiment”.
bereksperimen
- ber-
  - eksperimen → intransitive verb “to experiment”.
- No object after it: you just “experiment”.

In this sentence you can say either:

saat melakukan eksperimen – while conducting experiments
saat bereksperimen – while experimenting

Both are natural; melakukan eksperimen sounds a bit more formal/literal.

Why is it kacamata pelindung and not pelindung kacamata? What exactly does pelindung do here?

Indonesian usually puts the main noun first, then the modifier.

kacamata = eyeglasses / goggles (literally “eye‑glass”, but as one word).
pelindung = “protector / protective” (from lindung “protect” + prefix pe-).

So:

kacamata pelindung = “protective glasses/goggles”
(glasses that protect something, usually your eyes).

If you say pelindung kacamata, it changes the meaning to:

pelindung kacamata = “protector for glasses” (e.g. a glasses case or cover).

So the order matters:

kacamata pelindung: the glasses are protective.
pelindung kacamata: something else protects the glasses.

Why is it sarung tangan karet and not a plural like “rubber gloves”? How do plurals work here?

Indonesian usually does not mark plural on nouns unless it needs emphasis.

sarung tangan literally: “hand cover” → means “glove / gloves”.
By default it already implies a pair when context is clear.
karet = “rubber”, placed after it as a modifier → “rubber gloves”.

So sarung tangan karet naturally means “rubber glove(s)” in general.
To emphasize plurality, you can add words like:

beberapa sarung tangan karet = several rubber gloves
dua pasang sarung tangan karet = two pairs of rubber gloves

You do not usually say “sarung-sarung tangan karet” here.

Why don’t we say kacamata yang melindungi instead of kacamata pelindung?

You can say kacamata yang melindungi mata (“glasses that protect the eyes”), but that is a full relative clause and sounds more descriptive/long.

For common, established combinations, Indonesian prefers a short noun + modifier structure:

kacamata pelindung = “protective glasses” (fixed, compact phrase)
sarung tangan karet = “rubber gloves”

The yang construction is used more when:

the modifier is a full clause: kacamata yang dia pakai (the glasses he/she wears)
you want to emphasize or specify more information.

In this sentence, kacamata pelindung is simple and idiomatic.

If I want to emphasize that the action is happening right now, should I add sedang or lagi before memakai?

You can, depending on the nuance:

Dia sedang memakai kacamata pelindung …
Dia lagi memakai kacamata pelindung … (more informal/colloquial)

sedang marks an action in progress, similar to English “is doing”.
lagi can also mark “in the middle of doing something” in casual speech.

However, with verbs like memakai, adding sedang can sometimes sound like you’re describing the process of putting them on, not just the state of already wearing them.

In many contexts, Dia memakai kacamata pelindung… by itself is natural for:

“He/she wears protective goggles when …” (habit)
“He/she is wearing protective goggles when …” (describing a situation)

Use sedang only if you really want to highlight the action as ongoing at that moment.

Could I move saat melakukan eksperimen to the beginning of the sentence? Would that change the meaning?

Yes, you can change the word order without changing the meaning:

Dia memakai kacamata pelindung dan sarung tangan karet saat melakukan eksperimen.
Saat melakukan eksperimen, dia memakai kacamata pelindung dan sarung tangan karet.

Both mean the same thing. Putting saat melakukan eksperimen first just emphasizes the time/condition (“When doing experiments…”) a bit more, which is very natural in both spoken and written Indonesian.

Should there be another dia before melakukan? For example: dia memakai … saat dia melakukan eksperimen?

You can repeat dia, but you don’t have to. Both are correct:

Dia memakai kacamata pelindung dan sarung tangan karet saat melakukan eksperimen.
Dia memakai kacamata pelindung dan sarung tangan karet saat dia melakukan eksperimen.

In Indonesian, when the subject of the second verb is obviously the same as the subject of the first, it’s very common to omit the second subject. This keeps the sentence more natural and less repetitive. The original sentence is perfectly standard.

What’s the difference between eksperimen and percobaan in this context? Could we say saat melakukan percobaan?

Yes, you can say saat melakukan percobaan. The meaning would still be “while doing experiments”.

Nuances:

eksperimen
- Loanword from European languages.
- Sounds a bit more scientific/technical.
percobaan
- Native Indonesian word (from coba “try”).
- Can mean “experiment”, but also “trial / attempt / try”.

In a scientific context, eksperimen feels more precise, but percobaan is also widely used in school science and everyday talk about experiments.