اذا ما انت فاضي هلا، استنى شوي.

Here, إذا means if, and ما makes the following idea negative. So إذا ما... means if ... not or if you aren't....

In Levantine, this is a very common way to start a negative conditional sentence.

Arabic does not use a present-tense verb to be the way English does. So instead of saying you are free, Levantine says literally you free:

إنت فاضي = you are free / available / not busy

That is why انت is important here: it gives you the subject, since there is no separate word for are.

فاضي literally means empty, but in everyday speech it very often means:

• free
• available
• not busy
• having time

In this sentence it is the masculine singular form. If you were talking to a woman, you would say فاضية.

That is a very good question.

In Levantine, the normal negation of an adjective or noun phrase is often:

• مو فاضي
• مش فاضي

But after إذا, many speakers also use إذا ما... in conditional sentences. So in real speech you may hear more than one pattern, depending on region and speaker.

So all of these can exist in colloquial Levantine-style speech:

• إذا ما إنت فاضي...
• إذا مو فاضي...
• إذا مش فاضي...

They are not all identical in style or regional flavor, but they are all understandable.

هلا means now or right now in Levantine Arabic.

It is a very common colloquial word. Depending on the country or speaker, you may also hear forms like:

• هلق
• هلّق
• هسّا or إسّا in some areas

So هلا is a strongly dialectal word, not Modern Standard Arabic.

استنى is an imperative, meaning it is a command: wait.

In this sentence, it is addressed to one man.

Common related forms are:

• استنى = wait! (to one man)
• استنّي = wait! (to one woman)
• استنّوا = wait! (to more than one person)

In formal Arabic, you would more likely see انتظر instead, but استنى is very natural in Levantine speech.

شوي means a little, a bit, or for a short while.

So استنى شوي is a very common expression meaning:

• wait a bit
• wait a little
• hold on a second

In everyday speech, شوي is one of the most common colloquial words for a little / a bit.

To a woman:

إذا ما إنتِ فاضية هلا، استنّي شوي.

To more than one person:

إذا ما إنتو فاضيين هلا، استنّوا شوي.

Notice the changes:

• إنت → إنتِ → إنتو
• فاضي → فاضية → فاضيين
• استنى → استنّي → استنّوا

A rough pronunciation is:

iza ma enta faaDi halla, stanna shway

A few notes:

• اذا → iza
• انت is often enta or inta
• فاضي has the letter ض, which is a heavier, emphatic d
• هلا sounds like halla
• استنى is often heard like stanna
• شوي may sound like shway or shwei, depending on the speaker

Yes. Arabic is often flexible with word order.

The version you have starts with the condition:

إذا ما انت فاضي هلا، استنى شوي.

But in conversation, people can also move the command first if the flow feels natural:

استنى شوي إذا ما انت فاضي هلا.

Starting with the if-clause is very common, though, and it sounds completely natural.