ينتظر الخياط خارج المتجر.

Because Arabic very often uses verb–subject order, especially in straightforward statements.

So:

• ينتظر الخياط = The tailor waits / is waiting
• Literally: waits the-tailor

This is a normal Arabic sentence pattern called a verbal sentence.

You can also say:

• الخياط ينتظر خارج المتجر

That is also correct, but it sounds more like a noun-initial sentence, with slightly more focus on the tailor.

ينتظر is the present/imperfect form of the verb انتظر = to wait.

Here it means:

• he waits
• he is waiting

Why he?

Because the subject الخياط is:

• singular
• masculine

So the verb must be 3rd person masculine singular.

A full breakdown:

• يـ = marks he
• ينتظر = he waits / he is waiting

In context, Arabic present tense can often mean either:

• simple present: he waits
• present progressive: he is waiting

In Arabic, the verb itself already carries the meaning, so you do not need a separate word for is here.

English says:

• The tailor is waiting

Arabic simply says:

• ينتظر الخياط

Arabic does not normally use a present-tense equivalent of is in sentences like this.

So the idea of is waiting is built into the context and the present-tense verb.

الخياط means the tailor.

It is pronounced roughly:

• al-khayyāṭ

A few useful notes:

• الـ = the
• the core noun is خيّاط = tailor
• the يّ has a doubled y sound
• the final ط is an emphatic t

So it is not just khayat. It is more like:

• kha-yyaat

with a stronger/doubled y.

Because it is definite: the tailor, not a tailor.

In Arabic:

• خياط = a tailor / tailor
• الخياط = the tailor

The prefix الـ is the Arabic definite article, equivalent to English the.

خارج here means outside, and in this sentence it functions as an adverbial expression of place.

So:

• خارج المتجر = outside the store

In Arabic grammar, this is often treated like a noun of place / ظرف مكان in an iḍāfa-like structure:

• خارج = outside
• المتجر = the store

Together: outside the store

So even though English often uses a preposition like outside, Arabic here uses خارج directly before the noun.

Because خارج itself already sets up the relationship of place.

Arabic says:

• خارج المتجر

not:

• خارج من المتجر for this meaning

This is similar to expressions where one word naturally connects to the following noun.

So المتجر is linked directly to خارج and means:

• outside the store

Because it comes after خارج in an iḍāfa-type relationship.

In full case endings, the sentence would be:

• ينتظرُ الخيّاطُ خارجَ المتجرِ

Here:

• الخيّاطُ is nominative because it is the subject
• خارجَ is accusative as an adverbial of place
• المتجرِ is genitive because it is the second term after خارج

Even if short vowels are not written in normal text, this grammatical relationship is still there.

A fully vowelled version would be:

• يَنْتَظِرُ الخَيَّاطُ خَارِجَ الْمَتْجَرِ

This shows the grammatical endings more clearly:

• ينتظرُ
• الخياطُ
• خارجَ
• المتجرِ

In everyday printed Arabic, these short vowels are usually omitted, so you normally see:

• ينتظر الخياط خارج المتجر

Because it means the store, not a store.

So:

• متجر = a store
• المتجر = the store

The sentence as written specifically means:

• outside the store

If you wanted outside a store, you could say:

• خارج متجرٍ

So the presence of الـ tells you the noun is definite.

Yes, absolutely.

Both are correct:

• ينتظر الخياط خارج المتجر
• الخياط ينتظر خارج المتجر

The difference is mainly one of word order and focus:

• ينتظر الخياط... = more neutral, verb-first style
• الخياط ينتظر... = starts by highlighting the tailor

Both mean the same thing in basic translation.

Not necessarily. In this sentence, the verb is used without stating what the tailor is waiting for.

So the sentence simply means:

• The tailor is waiting outside the store

Arabic can leave the object unstated when it is unknown, unimportant, or obvious from context.

If you wanted to add an object, you could say something like:

• ينتظر الخياط الزبون خارج المتجر
  The tailor is waiting for the customer outside the store

So in your sentence, the action waiting is the main point, not what he is waiting for.