الموظف بالمكتب نسي النسخة على الطاولة.

A common Levantine-style pronunciation would be:

il-mwazzaf bil-maktab nesi / nese in-nuskha ʿaṭ-ṭawle

A few notes:

• نسي may sound like nesi or nese, depending on the region.
• على الطاولة is often reduced in speech to عالطاولة, so you may hear ʿaṭ-ṭawle or ʿal-ṭawle in fast speech.
• The symbol ʿ represents the Arabic letter ع.

It is perfectly understandable in Levantine, but the written form looks a little more neutral or semi-formal than very casual dialect writing.

In everyday Levantine, people often write or say:

• الموظف بالمكتب نسي النسخة عالطاولة

So the main thing that feels more formal here is على الطاولة written in full instead of the more spoken عالطاولة.

In Levantine, بـ is very commonly used to mean in, at, or inside.

So:

• بالمكتب = in the office / at the office

This is made of:

• بـ = in/at
• الـ = the
• مكتب = office

You could also say في المكتب, but بالمكتب is very natural in Levantine speech.

By itself, مكتب can mean either office or desk, depending on context.

In this sentence, office is the more likely meaning, because الموظف بالمكتب naturally sounds like the employee in the office or the employee at the office.

If the context were different, مكتب could also mean a physical desk.

Because in spoken Levantine, على + الـ often contracts to عالـ.

So:

• على الطاولة becomes عالطاولة

This is extremely common in speech.
So if you learn the full form على الطاولة, that is good, but you should also recognize the spoken form عالطاولة.

This happens because of sun letters.

When الـ comes before certain letters, the l sound of the article disappears and the next consonant is doubled.

Here:

• ن in النسخة is a sun letter, so it is pronounced en-nuskha / in-nuskha
• ط in الطاولة is also a sun letter, so it is pronounced eṭ-ṭawle

But in:

• الموظف
• المكتب

the letter م is a moon letter, so the l sound stays: il-mwazzaf, bil-maktab.

Because Levantine often uses subject-first word order in everyday speech.

So:

• الموظف بالمكتب نسي النسخة...
  is very natural.

A verb-first version is also possible:

• نسي الموظف بالمكتب النسخة...

Starting with الموظف makes it feel a bit like:

• The employee in the office forgot the copy...

That kind of topic-first structure is very common in spoken Arabic.

Literally, نسي means forgot.

But in a sentence like this, English often understands it as left behind by mistake. So the meaning can be:

• The employee forgot the copy on the table
• or more naturally in English, The employee left the copy on the table

So the Arabic verb is still forgot, but the real-life meaning can imply accidentally left behind.

Because النسخة comes directly after the verb نسي with no preposition, so it is the direct object.

Structure-wise:

• الموظف بالمكتب = the employee in the office
• نسي = forgot
• النسخة = the copy
• على الطاولة = on the table

So على الطاولة is a location phrase, while النسخة is the thing affected by the verb.

Usually it describes the location of the copy: the copy was on the table.

So the most natural understanding is:

• the employee forgot the copy, and the copy was on the table

In real context, this often implies:

• he left it there

Like in English, context helps decide the exact nuance, but the normal reading is that the copy was on the table.

In Levantine, final ـة is usually pronounced as a short -a or -e, depending on the word and the local accent.

So you may hear:

• نسخة as nuskha
• طاولة as ṭawle

This is normal in dialect.
Also, when this ending is followed by another ending or used in certain grammatical combinations, it can sound like -t instead.