امي لسه بالسوق، بس انا بالبيت.

In Levantine Arabic, as in Arabic generally, the verb to be is usually left out in the present tense.

So instead of saying something like:

• My mother is still at the market
• I am at home

Arabic simply says:

• امي لسه بالسوق
• انا بالبيت

This is completely normal.
If you want past or future, then Arabic does use forms of to be:

• امي كانت بالسوق = My mother was at the market
• امي رح تكون بالسوق = My mother will be at the market

So in the present, no is/am/are is needed.

Here, لسه means still.

So امي لسه بالسوق means your mother is still at the market, meaning she has not come back yet.

A useful thing to know is that لسه can have slightly different meanings depending on context, such as:

• still
• yet
• sometimes just or just now in some dialects/contexts

But in this sentence, the natural meaning is clearly still.

The بـ at the beginning is a very common preposition in Levantine Arabic. It often means in, at, or sometimes with, depending on context.

So:

• بالسوق = in/at the market
• بالبيت = in/at home

In Levantine, using بـ for location is extremely common and natural.
You may also learn في for in, but in everyday Levantine, بـ is often what people actually use in sentences like this.

So this sentence sounds very natural in spoken Levantine.

Arabic prepositions often attach directly to the following word.

So:

• ب + السوق becomes بالسوق
• ب + البيت becomes بالبيت

This is just normal Arabic spelling behavior.
Short prepositions like بـ often connect to the noun right after them.

It is similar to how Arabic also writes things like:

• للبيت = to the house
• بالمدرسة = at school

So the attached form is expected.

This happens because of the Arabic definite article الـ and how it behaves before certain consonants.

بالبيت

Underlyingly, this is:

• ب + البيت

The ل of ال stays pronounced, so you get something like:

• bil-bēt

بالسوق

Underlyingly, this is also:

• ب + السوق

But س is a sun letter, so the ل of ال is not pronounced. Instead, the س is emphasized/doubled in pronunciation. So it sounds like:

• bis-sūʔ or similar

So:

• بالبيت → bil-bēt
• بالسوق → bis-sūʔ

This is a very common Arabic pattern, not something special about this sentence only.

Yes, it could be dropped in some contexts, but here أنا is very natural because it adds contrast:

• امي لسه بالسوق، بس انا بالبيت

This feels like:

• My mother is still at the market, but I’m at home

The انا helps highlight the contrast between my mother and me.

If you said just:

• امي لسه بالسوق، بس بالبيت

that would sound incomplete or unclear, because Arabic usually wants the contrasted subject to be explicit here.

So انا is there for clarity and emphasis, not because Arabic always requires subject pronouns.

Here, بس means but.

So the sentence is contrasting two situations:

• امي لسه بالسوق = one situation
• انا بالبيت = a different situation

That is why بس = but here.

A good thing to remember is that بس can also mean only in other contexts. For example:

• بس هيك = only that / that’s all

So بس is a very common word with more than one meaning.
In this sentence, because it links two contrasting clauses, it clearly means but.

In careful spelling, especially in Modern Standard Arabic, you may see أمي.

In everyday Levantine writing, people often write more informally, and hamzas are very often omitted. So امي is extremely common in casual writing.

Also, in Levantine pronunciation, this word is usually pronounced more like:

• immi
• sometimes emmi, depending on region

That is different from the more formal Standard Arabic pronunciation:

• ummī

So there are really two things happening:

1. Informal spelling often drops the hamza.
2. Levantine pronunciation is different from Standard Arabic.

A common pronunciation would be something like:

immi lissa bis-sūʔ, bas ana bil-bēt

A few notes:

• امي → immi
• لسه → often lissa or something close, though pronunciation varies by region
• بالسوق → bis-sūʔ
• بس → bas
• بالبيت → bil-bēt

Also, in many Levantine varieties, the final consonant in سوق is not a strong q sound like in Standard Arabic. It is often pronounced as a glottal stop ء, so sūʔ is a good rough guide.

A more Standard Arabic version would be something like:

أمي ما زالت في السوق، لكنني في البيت.

or more simply:

أمي ما زالت في السوق، لكن أنا في البيت.

Main differences:

• لسه is colloquial; Standard Arabic would more likely use ما زالت
• بس is colloquial; Standard Arabic would more likely use لكن
• Levantine often uses بـ for location, while Standard Arabic more often uses في
• امي in casual Levantine writing would more formally be أمي

So the original sentence is clearly natural spoken Levantine, not formal written Arabic.