الجار الجديد يسكن في هذا الحي قرب السوق.

Because in Arabic, adjectives normally come after the noun they describe.

So:

• الجار = the neighbor
• الجديد = the new

Together, الجار الجديد literally follows the pattern the neighbor the-new, but in natural English we say the new neighbor.

Also, the adjective must agree with the noun in:

• definiteness
• gender
• number
• case

Because the noun is definite, the adjective must also be definite.

So:

• جار جديد = a new neighbor
• الجار الجديد = the new neighbor

This is a very common rule in Arabic: if the noun has الـ, the adjective describing it usually has الـ too.

يسكن is the imperfect form, which often corresponds to the English present.

Here it means something like:

• lives
• is living
• resides

In this sentence, the most natural English meaning is lives.

The verb comes from the root س-ك-ن, which is connected with dwelling, being still, or residing.

Arabic can use more than one normal word order.

This sentence begins with the subject:

• الجار الجديد يسكن...
• literally: The new neighbor lives...

That is perfectly natural in Arabic.

You could also have a verb-first version such as:

• يسكن الجار الجديد...

Starting with the noun can make the sentence feel a bit more like it is introducing or focusing on the new neighbor as the topic.

Because حيّ is a masculine singular noun in Arabic.

So the correct demonstrative is:

• هذا = this, for masculine singular nouns

If the noun were feminine singular, Arabic would usually use:

• هذه = this, for feminine singular nouns

So:

• هذا الحي = this neighborhood

In Modern Standard Arabic, the usual pattern is:

• demonstrative + definite noun

So:

• هذا الحي = this neighborhood

That is the standard MSA order.
English speakers sometimes expect something like the neighborhood this, but Arabic does not normally build the phrase that way in standard usage.

Because في is a preposition, and prepositions in Arabic normally make the following noun genitive.

So in fully vocalized Arabic, you would have:

• في هذا الحيِّ

That final -i sound reflects the genitive case.

In everyday printed Arabic, short case endings are usually not written, so you often just see:

• في هذا الحي

without the final vowel marks.

It is often translated as near, but grammatically it is not exactly the same kind of word as English near.

In this kind of phrase, قرب is a noun meaning something like nearness or proximity, and it is used adverbially:

• قرب السوق = near the market

So the structure is roughly:

• قرب = near / in proximity
• السوق = the market

A learner can safely understand the whole phrase as near the market, even if the underlying grammar is a little different from English.

Because س is a sun letter.

With sun letters, the ل of الـ is not pronounced separately. Instead, the following consonant is doubled in pronunciation.

So:

• السوق is written with ال
• but pronounced as-sūq

By contrast, words beginning with moon letters keep the l sound, such as:

• الجار = al-jār
• الحي = al-ḥayy

It is pronounced roughly al-ḥayy.

A few things matter here:

• The ح is a deep, breathy h sound from the throat, not the ordinary English h.
• The final ي is effectively doubled in careful pronunciation, so it sounds like -yy.
• In a fully vocalized genitive form after في, it would be الحيِّ, pronounced something like al-ḥayyi.

So this word is not just al-hai. The doubled y sound is important.

No. حيّ can mean different things depending on context.

For example:

• as a noun, it can mean district or neighborhood
• as an adjective, it can mean alive or living

In this sentence, the context makes the meaning clear:

• في هذا الحي = in this neighborhood

So here it is definitely the noun neighborhood, not the adjective alive.