ينصب صديقي الخيمة خلال عطلة نهاية الأسبوع.

Because Arabic often likes verb-subject-object order, especially in Modern Standard Arabic.

So this sentence is literally structured as:

• ينصب = sets up / pitches
• صديقي = my friend
• الخيمة = the tent

This is completely normal Arabic. You could also say:

• صديقي ينصب الخيمة خلال عطلة نهاية الأسبوع

That is also correct, but it puts a little more focus on my friend. Starting with the verb feels a bit more action-focused.

ينصب is the imperfect form of the verb نصب.

Here it is:

• 3rd person
• masculine
• singular

So it means he sets up / he pitches / he erects.

In this sentence, it matches صديقي because صديقي is singular and masculine.

The imperfect in Arabic can express:

• simple present
• habitual action
• sometimes near future, depending on context

So ينصب does not always mean only is setting up right now.

صديقي comes from:

• صديق = friend
• ـي = my

So صديقي means my friend.

That final -ي is a attached possessive pronoun. Arabic often expresses possession this way, instead of using a separate word for my.

Because a noun with a possessive suffix is already definite.

So:

• صديق = a friend / friend
• صديقي = my friend

Since my friend is already specific, Arabic does not add الـ.
So الصديقي would be wrong here.

Because نصب is a transitive verb here. It takes a direct object directly.

So:

• ينصب صديقي الخيمة = My friend pitches the tent

There is no need for a word like to or on before الخيمة.

If the sentence were fully vocalized, الخيمة would normally be in the accusative because it is the direct object:

• الخيمةَ

In normal Arabic writing, those short case vowels are usually not written.

Because it means the tent, not a tent.

Arabic uses الـ to mark definiteness.

So:

• خيمة = a tent
• الخيمة = the tent

This suggests a specific tent, or a tent already known from context.

خلال means during or throughout.

In this sentence:

• خلال عطلة نهاية الأسبوع = during the weekend

For a learner, it is easiest to think of خلال as a word that introduces a time period. The noun after it appears in the genitive construction:

• عطلةِ

It is an iḍāfa construction, often called a possessive or of-construction.

Breakdown:

• عطلة = vacation / break / holiday
• نهاية = end
• الأسبوع = the week

So literally it is something like:

• the break of the end of the week

That is the standard Arabic way to express the weekend.

So the whole phrase عطلة نهاية الأسبوع functions as one time expression.

Because in an iḍāfa construction, the earlier nouns usually do not take الـ.

So you get:

• عطلة
• نهاية
• الأسبوع

The definiteness comes from the last noun. Since الأسبوع is definite, the whole phrase becomes definite.

That is why Arabic says:

• عطلة نهاية الأسبوع

not:

• العطلة النهاية الأسبوع

The first form is the correct iḍāfa structure.

It could be either, depending on context.

ينصب can mean:

• my friend pitches the tent
• my friend is pitching the tent
• my friend will pitch the tent

Arabic often relies on context for this.

If you want to make the future clearer, you can add سـ or سوف:

• سينصب صديقي الخيمة خلال عطلة نهاية الأسبوع
• سوف ينصب صديقي الخيمة خلال عطلة نهاية الأسبوع

Both mean My friend will pitch the tent during the weekend.

Yes. That sentence is also correct.

Compare:

• ينصب صديقي الخيمة خلال عطلة نهاية الأسبوع
• صديقي ينصب الخيمة خلال عطلة نهاية الأسبوع

Both mean the same thing. The difference is mainly in emphasis and style:

• verb first: more neutral or action-centered, very common in MSA
• subject first: gives a little more focus to my friend

So both are good Arabic.