هذا فريق الزملاء الذين يعملون هنا.

It is not stated explicitly. In Arabic, present-tense sentences of the type X is Y often have no written or spoken verb to be.

So:

• هذا = this
• فريق الزملاء الذين يعملون هنا = the noun phrase that tells you what this is

In other words, Arabic simply says the equivalent of this, the team of the colleagues who work here, and English adds is when translating.

Because هذا agrees with the grammatical head noun, which is فريق.

• فريق means team
• فريق is grammatically singular masculine
• so the demonstrative is هذا = this

Arabic is not pointing to the individual colleagues directly here. It is pointing to the team as one unit.

So the logic is:

• this team
• not these colleagues

Because فريق is a collective noun, like team in English.

Even though a team contains several people, the noun itself is singular. English works similarly:

• This team is strong
• not necessarily This team are strong in standard American English

So in Arabic, فريق is singular in form, even if the people inside it are plural in meaning.

Because فريق الزملاء is an iḍāfa construction, often called a construct phrase.

That means:

• فريق = first noun
• الزملاء = second noun, showing possession or association
• together: the team of the colleagues

In an iḍāfa:

• the first noun usually does not take الـ
• the second noun can be definite with الـ
• if the second noun is definite, the whole phrase becomes definite

So فريق الزملاء is already definite because الزملاء is definite.

It is in the genitive because it is the second term of the iḍāfa.

With full case endings, the phrase is:

• فريقُ الزملاءِ

So:

• فريقُ is nominative here as the predicate of the sentence
• الزملاءِ is genitive because it depends on فريق

A learner does not always need to pronounce the endings in everyday reading practice, but grammatically that is what is happening.

الذين is the relative pronoun meaning who for a masculine human plural antecedent.

Here it refers to الزملاء = the colleagues, not to فريق.

That is why the sentence means:

• This is the team of the colleagues who work here

The structure is:

• الزملاء
• الذين يعملون هنا
• = the colleagues who work here

Because the noun being described is الزملاء, which is plural.

Arabic relative pronouns must agree with the noun they refer to. So:

• الذي = singular masculine
• الذين = plural masculine human

Since الزملاء is a plural human noun, الذين is the correct choice.

If you wanted the relative clause to describe فريق instead, you would use singular masculine:

• هذا الفريق الذي يعمل هنا
• This is the team that works here

That is a different meaning.

Because it agrees with الذين, whose antecedent is الزملاء.

So the agreement is:

• الزملاء = plural
• الذين = plural relative pronoun
• يعملون = plural verb, they work

This is another clue that the relative clause is describing the colleagues, not the team.

If it described فريق, the verb would normally be singular:

• الذي يعمل
• that works

In this sentence, it describes the colleagues.

The clearest sign is the grammar:

• فريق is singular
• but الذين and يعملون are plural

So the relative clause cannot naturally be referring to فريق. It refers to الزملاء.

That means the sentence is specifically:

• This is the team of the colleagues who work here

not:

• This is the team that works here

To say the team that works here, you would normally say:

• هذا الفريق الذي يعمل هنا

Arabic often uses iḍāfa where English uses of.

So فريق الزملاء is a normal way to say:

• the team of the colleagues

You can also say فريق من الزملاء, but the nuance is a bit different. That often feels more like:

• a group of colleagues
• some colleagues
• a team made up of colleagues

So:

• فريق الزملاء = a tighter noun phrase, the colleagues’ team or the team of the colleagues
• فريق من الزملاء = more like a team/group consisting of colleagues

Because that is a very normal place for an adverb of place in Arabic.

The relative clause is:

• الذين يعملون هنا
• who work here

Arabic word order is somewhat flexible, but putting هنا after the verb is natural and neutral. It simply tells you where the action happens.

You could move elements around for emphasis in some contexts, but this word order is the most straightforward.

A careful reading with case endings would be approximately:

• hādhā farīqu z-zumalā’i alladhīna yaʿmalūna hunā

A few useful notes:

• فريق is farīq
• الزملاء is often pronounced with assimilation of الـ because ز is a sun letter, so you hear az-zumalā’ rather than al-zumalā’
• الذين is alladhīna
• يعملون is yaʿmalūna

If you are reading without case endings, you will often hear something close to:

• hādhā farīq az-zumalā’ alladhīna yaʿmalūna hunā