فريق المتطوعين في نقطة التجمع.

Not necessarily. By itself, it is most naturally a noun phrase, not a full verbal sentence.

Arabic often uses noun phrases like this for:

• labels
• captions
• headings
• short scene descriptions

So this phrase can stand on its own in context, even without a verb. In a longer sentence, it could be part of something bigger, such as فريق المتطوعين في نقطة التجمع جاهز.

Because فريق المتطوعين is an iḍāfa construction, also called a construct phrase.

In an iḍāfa:

• the first noun usually does not take الـ
• the second noun tells you whose/what kind of thing it is

So:

• فريق المتطوعين = the team of the volunteers / the volunteer team

Even though فريق has no الـ, the whole phrase can still be definite because the second part is definite.

Because المتطوعين is in the genitive position.

Here it is the second noun in an iḍāfa, and the second noun of an iḍāfa is genitive.

Also, متطوعون is a sound masculine plural, and that plural changes like this:

• nominative: -ون
• accusative/genitive: -ين

So:

• المتطوعون = nominative
• المتطوعين = accusative or genitive

In this phrase, it is genitive, so -ين is the correct form.

Because in an iḍāfa, the restriction applies to the first noun, not the second.

So:

• the first noun: no الـ in normal iḍāfa
• the second noun: it can be definite with الـ, indefinite, or even a pronoun

That is why فريق المتطوعين is perfectly normal:

• فريق = first noun, so no الـ
• المتطوعين = second noun, so الـ is fine

It is grammatically singular.

Even though it refers to a group of people, فريق means team, which is a singular noun. So if you describe it with an adjective or refer back to it, Arabic normally treats it as singular masculine.

For example:

• فريق المتطوعين حاضر not a plural adjective

So the meaning includes many people, but the grammar is singular.

For the same reason: this is another iḍāfa.

• نقطة = point
• التجمع = the gathering / assembly

Together:

• نقطة التجمع = assembly point / gathering point

Since نقطة is the first noun of the iḍāfa, it normally does not take الـ. The whole phrase is definite because التجمع is definite.

So this sentence contains one iḍāfa inside another:

• فريق المتطوعين
• نقطة التجمع

في usually means in or at, depending on context.

In this phrase, English would often use at:

• at the assembly point

Grammatically, في is a preposition, and it makes the following noun genitive.

So after في:

• نقطة is genitive
• and because التجمع is the second noun of an iḍāfa, it is also genitive

If fully vowelled, that part would be:

• في نقطةِ التجمعِ

Yes, that is also possible, but it is not exactly the same style.

• فريق المتطوعين is the compact iḍāfa form
• فريق من المتطوعين uses من = of/from

The iḍāfa version often sounds more like a fixed label or established group name. The من version can sound a little more like:

• a team made up of volunteers
• one team from among the volunteers

So both can work, but فريق المتطوعين is very natural for a heading, sign, or short description.

Yes. التجمع is pronounced at-tajammuʿ, not al-tajammuʿ.

That is because ت is a sun letter, so the ل of الـ is assimilated in pronunciation.

By contrast, in المتطوعين, the م is a moon letter, so you do pronounce the l sound:

• al-mutaṭawwiʿīn in pause

A simple pause-style pronunciation of the whole phrase is approximately:

• farīq al-mutaṭawwiʿīn fī nuqṭat at-tajammuʿ

In careful fully inflected reading, the internal vowels would change according to case, but learners often first hear it in pause form.