لدى ابنتي حلم.

لدى is a common MSA word meaning something like with, in the possession of, or at the disposal of. In sentences like this, it is used to express the idea of having.

So the structure is literally closer to:

With my daughter is a dream

rather than:

My daughter has a dream

This is a very normal Arabic way to express possession.

In Arabic, possession is often expressed without a verb like English have.

Instead, Arabic commonly uses:

• لدى
• عند
• sometimes لِـ

So instead of saying my daughter has a dream with a special verb, Arabic says something like with my daughter [there is] a dream.

This is one of the big structural differences between English and Arabic.

ابنتي means my daughter.

It is made of:

• ابنة = daughter
• ـي = my

So:

ابنة + ي → ابنتي

The ـي here is a possessive suffix attached directly to the noun.

Because the final ة in ابنة is tāʾ marbūṭa.

When a word ending in ة is pronounced by itself, it often sounds like -a / -ah. But when you add a suffix, the t sound reappears.

So:

• ابنة = ibnah / ibna
• ابنتي = ibnatī = my daughter

This is very common in Arabic:

• سيارة → سيارتي
• مدرسة → مدرستي
• ابنة → ابنتي

Yes. بنتي also means my daughter.

The difference is mainly one of style and register:

• ابنتي is a bit more formal or literary
• بنتي is very common and natural too

In Modern Standard Arabic, both can appear, but ابنتي can sound slightly more formal in a sentence like this.

Because the sentence means a dream, not the dream.

So:

• حلم = a dream
• الحلم = the dream

In this kind of possession/existence sentence, the thing being introduced is often indefinite. Arabic is presenting it as something that exists in your daughter’s possession or mind: she has a dream.

If you said الحلم, it would usually refer to a specific, already known dream.

The order is:

• لدى ابنتي = a prepositional/locative expression
• حلم = the noun being stated to exist

So the structure is roughly:

With my daughter, a dream exists

In traditional grammar, حلمٌ is usually understood as the delayed subject (مبتدأ مؤخر) after the fronted phrase لدى ابنتي.

Arabic often puts this kind of phrase first, especially in sentences expressing existence or possession.

If fully vocalized, the sentence would be:

لَدَى ابْنَتِي حُلْمٌ

A few important points:

• ابنتي is attached to لدى in an iḍāfa-like relationship, so it is grammatically in the genitive position.
• Because it ends with ـي (my), the case ending is not clearly visible.
• حُلْمٌ is nominative, which is why it would take ـٌ in full vocalization.

So even though everyday Arabic writing usually leaves these endings unwritten, they are still part of the grammar.

A careful pronunciation is:

ladā ibnatī ḥulmun

You may also hear connected pronunciation where the initial helping vowel of ابنتي is reduced or dropped in continuous speech, sounding closer to:

ladā bnatī ḥulmun

For a learner, ladā ibnatī ḥulmun is a perfectly useful pronunciation to know.

It can mean either, depending on context.

So حلم may refer to:

• a dream while sleeping
• a dream in the sense of an aspiration or ambition

Arabic often leaves that to context. Since the meaning has already been provided to the learner, you should follow that intended meaning here.

Also, because Arabic script usually omits short vowels, the written form can sometimes cover more than one related word or nuance.

They are similar, but not always identical in tone.

• لدى is often a bit more formal and is common in writing
• عند is very common and broad in meaning

So:

• لدى ابنتي حلم
• عند ابنتي حلم

Both can work, but لدى sounds a little more formal or literary in Modern Standard Arabic.

Because normal Arabic writing usually omits them.

So you see:

لدى ابنتي حلم.

instead of the fully vocalized version:

لَدَى ابْنَتِي حُلْمٌ

This is completely normal in Arabic texts. Learners have to get used to reading words without most short vowels being shown.