Bring iemand saam.

Yes. Bring is the imperative form, so the sentence is giving an instruction or invitation.

Afrikaans usually makes commands with the plain verb:

• Kom!
• Wag!
• Bring iemand saam!

There is no extra word like English do.

The subject is an understood you.

In Afrikaans, commands often leave out the pronoun, so Bring iemand saam. could be said to:

• one person: jy
• more than one person: julle
• a formal you: u

The verb form stays the same. Context tells you who is being addressed.

Because saambring behaves like a separable verb combination.

In a main clause or command, the finite verb goes near the front, while saam stays later:

• Bring iemand saam.
• Hy bring iemand saam.

So English speakers may expect something like bring along someone, but Afrikaans naturally puts saam after the object here.

It depends on the sentence structure.

You often see it split when the verb is the main finite verb:

• Bring iemand saam.
• Hy bring iemand saam.

You often see it together in other forms:

• Ek wil iemand saambring.
• Ek het iemand saamgebring.

With te, it is normally split again:

• om iemand saam te bring

So in your sentence, writing bring and saam separately is correct.

Iemand is an indefinite pronoun meaning someone / somebody / anyone, depending on context.

Here it is the direct object of bring. It does not need an article, so you do not say 'n iemand.

You can replace it with something more specific:

• Bring Anna saam.
• Bring jou vriend saam.
• Bring hom saam.

Because saam is the normal word for along / together in this kind of expression.

Met means with, and it usually needs its own object:

• met my
• met jou
• met die kinders

So:

• Bring iemand saam. = natural everyday Afrikaans
• Bring iemand met jou saam. = bring someone along with you

The second version adds extra information and is not the basic pattern.

Sometimes, yes, but bring and neem are not exactly the same.

A simple way to think about it:

• bring = movement toward the destination or speaker
• neem = movement away from the starting point, like take

So if you are inviting someone to an event, Bring iemand saam is very natural.
If you are talking about what you will take with you somewhere, neem may be more natural in that context.

The easiest way is to add asseblief:

• Bring asseblief iemand saam.
• Bring iemand saam, asseblief.

Both are natural. The second one can sound a little softer.

You can also make it less direct by turning it into a question:

• Kan jy iemand saambring?

For a negative command, Afrikaans uses moenie ... nie:

• Moenie iemand saambring nie.

Notice that here saambring is written together.

So:

• positive command: Bring iemand saam.
• negative command: Moenie iemand saambring nie.