اشتريت دفترين زيادة لانه اختي كمان بدها تدرس.

Because دفترين is the dual form: it means two notebooks.

In Arabic, when you mean exactly two of something, you often use a special dual ending instead of the regular plural.

• دفتر = one notebook
• دفترين = two notebooks
• دفاتر = notebooks / more than two notebooks

In Levantine, -ين is very commonly used for the dual in everyday speech, especially in forms like this.

Here زيادة means extra or in addition.

So:

• دفترين زيادة = two extra notebooks

It comes after the noun phrase, which is very natural in Arabic.
Compare:

• اشتريت دفترين زيادة = I bought two extra notebooks

In English, we usually put extra before the noun, but in Arabic it often comes after.

لانه is the colloquial Levantine way of saying because he/it is, but in this sentence it works like because introducing the reason.

More formally, in Standard Arabic you would usually see:

• لأنّ = because
• or لأنّ أختي...

In Levantine writing, people often spell it more casually as لانه or لأنه, even when the meaning is just because.

So here:

• لانه اختي كمان بدها تدرس
• = because my sister also wants to study

This is normal dialect usage, not a mistake.

This is mostly a spelling simplification common in informal Arabic writing.

The more careful spelling is:

• أختي = my sister

But in chats, texts, and informal dialect writing, people often drop the hamza and write:

• اختي

They mean the same thing.
So:

• اختي = أختي = my sister

كمان means also, too, or as well.

In this sentence:

• اختي كمان = my sister too / my sister also

It adds the idea that someone else is studying too, or that the sister is included as well.

Very common Levantine word:

• أنا كمان = me too
• بدّي كمان = I want more / I want some too

بدها is a very common Levantine form meaning she wants or she needs / she is going to, depending on context.

It breaks down like this:

• بد = want / need
• -ها = her

So literally it is something like it is wanted by her / for her, but learners should usually just understand it as:

• بدها = she wants

Other forms:

• بدي = I want
• بدك = you want
• بده = he wants
• بدها = she wants
• بدنا = we want
• بدهم = they want

Here:

• اختي كمان بدها تدرس
• = my sister also wants to study

Because بدها is followed by a verb in the present form to express wanting to do something.

So:

• بدها تدرس = she wants to study

This is one of the most useful Levantine patterns:

• بدي آكل = I want to eat
• بدك تروح؟ = Do you want to go?
• بدهم يدرسوا = They want to study

There is no separate word for to like English to study. Arabic just uses the verb directly.

Yes — this is a very common source of confusion.

In the present tense, تـ can mark either:

• you (masculine singular), or
• she

So تدرس can mean either:

• you study
• or she studies

The context tells you which one is meant.

Here the subject is اختي = my sister, so تدرس must mean:

• she studies / she wants to study

Because it follows بدها, the meaning becomes:

• she wants to study

Arabic does not need an extra word like English that here.

The structure is simply:

• لانه اختي كمان بدها تدرس
• literally: because my sister also wants to study

That is already complete and natural in Arabic.

English sometimes uses because she wants to..., sometimes because it’s the case that..., but Arabic usually just goes straight into the clause.

Yes, very natural.

The sentence is:

• اشتريت دفترين زيادة لانه اختي كمان بدها تدرس.

A natural breakdown is:

• اشتريت = I bought
• دفترين زيادة = two extra notebooks
• لانه = because
• اختي كمان = my sister also
• بدها تدرس = wants to study

So the overall pattern is:

I bought + object + reason

This is a normal and common way to build sentences in Levantine.

Yes. A more Standard Arabic version could be something like:

• اشتريت دفترين إضافيين لأن أختي أيضًا تريد أن تدرس.

But that sounds much more formal and less conversational.

The original Levantine sentence:

• اشتريت دفترين زيادة لانه اختي كمان بدها تدرس.

is much more natural for everyday speech.

Some common dialect vs formal differences here are:

• زيادة instead of إضافيين
• كمان instead of أيضًا
• بدها instead of تريد
• informal لانه / لأنه instead of more careful formal usage

A rough pronunciation would be:

• ishtarēt daftareen ziyāde la’anno ekhti kamān biddha tidros

A few notes:

• اشتريت is often pronounced something like ishtarēt
• دفترين = daftareen
• لانه often sounds like la’anno or la2anno
• اختي = ekhti or ikhti, depending on region
• بدها often sounds like biddha
• تدرس may sound like tidros

Pronunciation varies across Levantine regions, but this gives a useful learner-friendly approximation.

Yes, depending on context, بدها can sometimes feel close to:

• she wants to
• she is going to
• she needs to

But in this sentence, the most natural reading is:

• my sister also wants to study

Because the speaker bought extra notebooks for her, the idea is probably that she wants to study too, so the speaker bought supplies for her as well.

So while بدها can be flexible, wants to is the best translation here.