Pegawai keselamatan itu datang.

In Malay, the main noun usually comes first, and the word that describes or narrows it comes after.

So:

• pegawai = officer / official
• keselamatan = safety / security

Together, pegawai keselamatan literally looks like officer security, but it means security officer.

This is very common in Malay:

• rumah besar = big house
• kereta polis = police car
• pegawai keselamatan = security officer

So compared with English, Malay often puts the describing noun after the main noun.

Itu is a demonstrative word. It often means that, but in many sentences it can also function a bit like the when the speaker is referring to a specific, known thing or person.

So:

• pegawai keselamatan = a security officer / security officer
• pegawai keselamatan itu = that security officer / the security officer

A key point for English speakers: in Malay, words like ini and itu usually come after the noun phrase, not before it.

• pegawai itu = that officer
• pegawai keselamatan itu = that security officer

Because that is the normal Malay pattern.

In English, you say:

• that officer

In Malay, you say:

• pegawai itu

And with a longer noun phrase, itu still goes at the end of the whole phrase:

• pegawai keselamatan itu

Not:

• itu pegawai keselamatan for this meaning

So the structure is:

noun + modifier + itu

This is a very important word-order habit to get used to in Malay.

By itself, datang does not mark tense. It can mean:

• come
• comes
• came
• is coming

The exact time usually depends on context, or on extra time words such as:

• sudah = already
• sedang = in the middle of / currently
• akan = will
• semalam = yesterday
• esok = tomorrow

So:

• Pegawai keselamatan itu datang.
  could mean The security officer came, comes, or is coming, depending on context.

If you want to make time clearer, you could say:

• Pegawai keselamatan itu sudah datang. = The security officer has already come.
• Pegawai keselamatan itu akan datang. = The security officer will come.

Because datang is already a verb meaning to come / to arrive, so no extra is is needed.

English often uses extra helping words, but Malay is usually more economical here.

Compare:

• English: The security officer is coming.
• Malay: Pegawai keselamatan itu datang.

Also, Malay often does not need a verb like to be in simple statements. That is a broader feature of the language.

So this sentence is complete without any word meaning is.

It can often be understood as both come and arrive, depending on context.

Malay datang is flexible. In many situations, English might choose either verb:

• Dia datang ke rumah saya. = He came to my house.
• Dia datang pada pukul 8. = He arrived at 8.

So in your sentence, datang could naturally be understood as came, comes, is coming, or arrived, depending on the situation.

Normally, no.

Seorang means a / one person who is..., so it introduces an indefinite person:

• seorang pegawai keselamatan = a security officer

But itu makes the noun phrase definite/specific:

• pegawai keselamatan itu = that / the security officer

These ideas usually do not go together in this way. So you would normally choose one or the other:

• Seorang pegawai keselamatan datang. = A security officer came.
• Pegawai keselamatan itu datang. = The/that security officer came.

It is built from the root selamat.

Common related forms are:

• selamat = safe; also used in greetings like selamat pagi
• keselamatan = safety / security

The pattern ke-...-an often creates an abstract noun in Malay.

So:

• selamat → safe
• keselamatan → safety / security

That is why pegawai keselamatan literally has the sense of officer of security/safety.

Yes. Pegawai is a fairly broad word. It can mean officer, official, or staff member, depending on context.

For example:

• pegawai polis = police officer
• pegawai bank = bank officer / bank staff member
• pegawai keselamatan = security officer

So the exact English translation may vary a little, but in this sentence security officer is a very natural choice.

Yes. This is a very normal Subject + Verb sentence:

• Pegawai keselamatan itu = the subject
• datang = the verb

So the sentence structure is:

[noun phrase] + [verb]

That is one of the most basic and common Malay sentence patterns.

By default, it is usually understood as one specific security officer, not several.

Malay does not always mark singular and plural as clearly as English does, but this sentence most naturally refers to one officer.

If you wanted to make it clearly plural, you could say something like:

• Pegawai-pegawai keselamatan itu datang. = Those security officers came.
• Para pegawai keselamatan itu datang. = The security officers came.

So without plural marking, learners should usually read this as singular unless context suggests otherwise.

A simple learner-friendly pronunciation is:

• Pegawai ≈ puh-GA-wai
• keselamatan ≈ kuh-suh-la-MA-tan
• itu ≈ ee-too
• datang ≈ DAH-tang

Very roughly together:

puh-GA-wai kuh-suh-la-MA-tan ee-too DAH-tang

A few useful notes:

• g is a hard g, as in go
• ng in datang is like the ng in sing
• Malay spelling is generally quite regular, so pronunciation is often easier than English spelling

You would replace itu with ini:

• pegawai keselamatan ini = this security officer

So:

• Pegawai keselamatan itu datang. = That/The security officer came.
• Pegawai keselamatan ini datang. = This security officer came.

Again, notice that ini also comes after the noun phrase, just like itu.