الملخص اللي كتبته الطالبة كان قصير، بس فيه كل شي مهم.

A useful way to split it is:

• الملخص = the summary
• اللي كتبته الطالبة = that the student wrote
• كان قصير = was short
• بس فيه كل شي مهم = but it had / contained everything important

So the full structure is:

• noun phrase: الملخص اللي كتبته الطالبة
• main statement: كان قصير
• contrast/addition: بس فيه كل شي مهم

This is a very common Arabic pattern: noun + relative clause + comment about it.

اللي is the Levantine relative word meaning that, which, or who.

So:

• الملخص اللي كتبته الطالبة = the summary that the student wrote

One important thing for learners: in Levantine, اللي is used for all genders and numbers. That is much simpler than formal Arabic, which has different forms like الذي and التي.

The ـه means it / him, and here it refers back to الملخص.

So كتبته الطالبة literally means:

• the student wrote it

Even though English says the summary that the student wrote, Arabic often keeps a pronoun inside the relative clause. This is very normal.

So the logic is:

• الملخص = the summary
• اللي كتبته الطالبة = that the student wrote it

That extra pronoun is a common feature of Arabic relative clauses.

Because verb + subject word order is very common in Arabic.

So:

• كتبته الطالبة = the student wrote it

This is completely natural. You could also put the subject first in some contexts, but after the verb is very common, especially in narrative or descriptive sentences.

كان is the past tense of to be.

So:

• كان قصير = was short

In Arabic, present-tense is/am/are is often omitted, but in the past you usually need كان.

Compare:

• الملخص قصير = the summary is short
• الملخص كان قصير = the summary was short

Because الملخص is a masculine noun.

In Arabic, adjectives agree with the noun they describe. Since الملخص is masculine singular, the adjective is also masculine singular:

• ملخص قصير = a short summary

If the noun were feminine, then you would expect قصيرة.

Here بس means but.

So:

• كان قصير، بس... = it was short, but...

In Levantine, بس is very common in everyday speech. It can also mean only / just in other contexts, so the meaning depends on the sentence.

Here the contrast makes it clearly mean but.

Here فيه literally means something like in it there is, but in natural English it often corresponds to it has or it contains.

So:

• بس فيه كل شي مهم = but it has / contains everything important

The ـه again refers to الملخص, so فيه is literally in it.

This is a very common Arabic way to express possession or contents, instead of using a direct verb like has.

Levantine Arabic often expresses having / containing with structures based on في.

So instead of saying something exactly parallel to English it has everything important, Arabic often says something closer to:

• in it, there is everything important

That is why فيه sounds very natural here.

This is one of those places where Arabic structure is a bit different from English, even when the meaning is straightforward.

كل شي is the common Levantine everyday form for everything or every thing.

• شي is the colloquial form
• شيء is the more formal / standard form

So:

• كل شي = natural everyday Levantine
• كل شيء = more formal, more standard

Both are understandable, but كل شي fits the Levantine tone of this sentence much better.

Because شي is singular in form, and كل شي behaves like everything / every thing.

So:

• كل شي مهم = everything important or literally every important thing

Arabic does not need a plural adjective here. The adjective matches شي, which is singular.

It is best understood as informal Arabic with Levantine features.

The clearest Levantine elements are:

• اللي instead of formal الذي / التي
• بس for but
• شي instead of شيء

At the same time, the spelling is still close to normal written Arabic, which is very common in texts, chats, subtitles, and teaching materials. So this kind of sentence sits in the middle: written in Arabic script, but clearly colloquial in flavor.

Because Arabic has moon letters and sun letters.

• In الملخص, م is a moon letter, so the ل of ال is pronounced.
• In الطالبة, ط is a sun letter, so the ل is not pronounced separately and the ط gets doubled.

So in pronunciation, learners often hear something like:

• الملخص → il-mulakhkhaṣ
• الطالبة → eṭ-ṭālbe

This is a pronunciation rule, not a spelling change.