يجب على مالك العقار أن يبلغ المستأجر بالإيجار الشهري ومبلغ الضمان.

This is a very common MSA pattern for expressing obligation.

• يجب = it is necessary / it is obligatory / must
• على + person = on/upon the person
• أن + present verb = the action that must be done

So:

• يجب على مالك العقار أن يبلغ...
• literally: It is obligatory upon the property owner to inform...
• natural English: The property owner must inform...

This pattern is especially common in formal, legal, and administrative Arabic.

Because Arabic often expresses obligation as something that rests on someone.

So:

• يجب على مالك العقار = it is required of the property owner
• more literally: it is obligatory upon the property owner

This is different from English, where we usually just say the owner must...

You will often see both patterns:

• يجب أن... = it is necessary to...
• يجب على فلان أن... = so-and-so must...

Because this is an iḍāfa construction, also called a genitive or possessive construction.

• مالك = owner
• العقار = the property / the real estate

Together:

• مالك العقار = owner of the property

In an iḍāfa:

1. the first noun usually does not take ال
2. the second noun can be definite with ال
3. the whole phrase can still be definite

So even though مالك has no ال, مالك العقار means the property owner, not just a property owner.

العقار is a formal word meaning real estate, property, or immovable property.

In this sentence, it refers to the rental property in a legal or contractual sense.

This is more formal than words like:

• بيت = house
• شقة = apartment

So مالك العقار sounds like legal/contract language: the owner of the property.

After يجب, Arabic commonly uses أن plus a present-tense verb to express the required action.

So:

• أن يبلغ = to inform / that he inform

This is the normal structure after many verbs and expressions of necessity, desire, possibility, etc.

Even though the text is unvocalized, the idea is that the verb after أن is in the subjunctive form.

So the sentence structure is:

• يجب = must / it is necessary
• أن يبلغ = to inform

Because unvocalized Arabic often leaves this kind of ambiguity, and you use context to decide.

The spelling يبلغ could represent different verbs depending on the vowels. But in this sentence, the structure tells you it means inform/notify:

• يبلغ المستأجر = inform the tenant
• بالإيجار الشهري ومبلغ الضمان = about the monthly rent and the deposit amount

That pattern fits inform someone about something, not reach.

So the meaning comes from the whole sentence, not from the bare consonants alone.

Because it is the direct object of the verb: the person being informed.

The structure is:

• يبلغ شخصًا بشيء
• inform someone of/about something

So here:

• المستأجر = the tenant = the person informed
• بالإيجار الشهري ومبلغ الضمان = about the monthly rent and the security deposit amount

This is similar to English:

• inform the tenant about the rent

Here بـ does not mean with in the physical sense. With verbs like this, it means something more like:

• about
• regarding
• concerning
• of

So:

• يبلغ المستأجر بالإيجار الشهري
• = inform the tenant about the monthly rent

This is a common thing in Arabic: a preposition may not translate literally, but instead forms part of the normal verb pattern.

Because الشهري is an adjective describing الإيجار.

In Arabic, adjectives usually:

1. come after the noun
2. agree with the noun in definiteness, gender, number, and case

So:

• الإيجار = the rent
• الشهري = monthly

Together:

• الإيجار الشهري = the monthly rent

Since الإيجار is definite (it has ال), the adjective الشهري must also be definite.

Because Arabic often allows one preposition to apply to two coordinated nouns.

So:

• بالإيجار الشهري ومبلغ الضمان means
• about the monthly rent and the deposit amount

The بـ is understood with both parts.

You could also repeat it for extra clarity:

• بالإيجار الشهري وبمبلغ الضمان

Both are understandable, but omitting the repeated preposition is very common.

This is another iḍāfa construction.

• مبلغ = amount / sum
• الضمان = guarantee / security

So:

• مبلغ الضمان = the amount of the security deposit or the deposit amount

In rental/legal contexts, الضمان often refers to the security deposit paid at the start of a lease.

This is very common in legal and formal Arabic.

Arabic often uses the definite article for roles in contracts, regulations, and official statements:

• المستأجر = the tenant
• العقار = the property

Even when the statement is general, these phrases refer to the relevant party in the situation or contract.

English sometimes does something similar:

• The tenant must...
• The landlord shall...

So the definiteness here does not necessarily mean a previously mentioned specific person in conversation; it can also be the standard legal way of naming a role.

Yes, this is definitely formal/legal MSA.

Signs of that include:

• يجب على... أن... for obligation
• العقار for property/real estate
• يبلغ for notify/inform
• مبلغ الضمان for deposit amount

In everyday speech, people would often use simpler or more colloquial wording, depending on the dialect.

So this is the kind of sentence you would expect in:

• contracts
• regulations
• notices
• administrative writing
• legal explanations