חלק מהאורחים יושבים בסלון, אבל חלק מהם במרפסת.

Because Hebrew is dividing the group into two subgroups:

• חלק מהאורחים = some of the guests
• אבל חלק מהם = but some of them

Using חלק twice creates a clear contrast: one part of the guests is in one place, and another part is somewhere else.

Literally, חלק means part, but in sentences like this it often means some.

מהאורחים is made of:

• מ־ / מן = from / of
• הָאורחים = the guests

So חלק מהאורחים literally means part of the guests, which in natural English is some of the guests.

The מ here is doing the job of of after חלק.

Because the sentence means some of the guests, not just some guests in general.

• חלק מהאורחים = some of the guests
• כמה אורחים = some guests

So the ה־ shows that we are talking about a specific known group of guests.

Hebrew often avoids repeating a noun if it is already clear.

• חלק מהאורחים = some of the guests
• חלק מהם = some of them

Here מהם means of them / from them, referring back to the guests.

This makes the sentence sound more natural and less repetitive.

מהם comes from:

• מ־ = from / of
• הם = they / them

Together, מהם means of them or from them.

So:

• חלק מהם = part of them = some of them

יושבים is masculine plural because it agrees with האורחים.

• singular masculine: יושב
• singular feminine: יושבת
• plural masculine: יושבים
• plural feminine: יושבות

The noun אורחים is masculine plural. Also, in Hebrew, a mixed-gender group usually takes masculine plural agreement.

Yes. יושבים is the present-tense form of the verb לשבת (to sit).

In Hebrew, present-tense forms often look like participles, but they function as normal present-tense verbs.

So יושבים can mean:

• sit
• are sitting

In this sentence, it means that the guests are seated in the living room.

Because Hebrew often omits repeated material when it is obvious.

The full version would be:

• חלק מהאורחים יושבים בסלון, אבל חלק מהם יושבים במרפסת.

But since יושבים is already understood from the first clause, Hebrew can leave it out:

• אבל חלק מהם במרפסת

This is very natural Hebrew. English can sometimes do something similar: Some of the guests are in the living room, but some are on the balcony.

Yes. That would be completely correct.

• אבל חלק מהם במרפסת = shorter, more economical
• אבל חלק מהם יושבים במרפסת = fuller, more explicit

Both are natural. The shorter version is common because the verb is easy to understand from the first clause.

The prefix ב־ means in / at / on, depending on context.

So:

• בסלון = in the living room
• במרפסת = on/in the balcony

It is the preposition ב־ attached directly to the noun.

Also, when ב־ attaches to a noun with ה־, they combine:

• ב + הסלון → בסלון
• ב + המרפסת → במרפסת

אבל means but. It shows contrast between the two groups:

• one group is in the living room
• another group is on the balcony

You could use ו (and) in some contexts, but אבל makes the contrast clearer and more natural here.

They are very close in meaning.

• חלק מהם = some of them
• חלקם = some of them / part of them

In many contexts, both are possible. For this sentence, you could say:

• חלק מהאורחים יושבים בסלון, אבל חלקם במרפסת.

That is also natural Hebrew.

However, חלק מהם may feel a little more explicit, especially for learners.

Yes, Hebrew allows some flexibility.

For example, you could also say:

• חלק מהאורחים יושבים בסלון, אבל במרפסת יושבים חלק מהם.

But the original sentence is simpler and more neutral.

The given word order is standard and natural:

• first name the subgroup
• then say where they are

It usually sounds like a current situation: where the guests are sitting right now.

That is because:

• יושבים naturally describes an ongoing state
• the sentence sounds like a description of a scene

So a listener would usually understand it as something happening at the moment being described.