المستأجر يبلغ مالك العقار بالمفتاح الاحتياطي.

The tenant is notifying the landlord about the spare key.

Breakdown of المستأجر يبلغ مالك العقار بالمفتاح الاحتياطي.

• مالك العقار: landlord; property owner
• مستأجر: tenant
• مفتاح احتياطي: spare key

Questions & Answers about المستأجر يبلغ مالك العقار بالمفتاح الاحتياطي.

Why is يبلغ understood as yuballighu here, not yablughu?

Because normal Arabic writing usually leaves out short vowels and the shadda, so يبلغ can represent more than one verb form.

In this sentence, it is understood as يُبَلِّغُ = informs / notifies / conveys to.

Without vowels, the same spelling could also be read as يَبْلُغُ = reaches / attains.
Context tells you which one is meant.

So here the full reading is:

المستأجرُ يُبَلِّغُ مالكَ العقارِ بالمفتاحِ الاحتياطيِّ

What is the basic structure of the sentence?

It is basically:

• المستأجر = the tenant
• يبلغ = informs / notifies
• مالك العقار = the property owner
• بالمفتاح الاحتياطي = about the spare key

So the structure is:

subject + verb + object + prepositional phrase

Why is مالك not written as المالك if it means the owner?

Because مالك العقار is an iḍāfa construction, also called a construct phrase.

In an iḍāfa:

• the first noun usually does not take ال