الحديقة جميلة.

A common Levantine-style pronunciation is il-ḥadīʔa jmīle.

A few useful notes:

• الـ is usually pronounced il- or el- in Levantine, not formal al-.
• In many urban Levantine accents, ق is pronounced as a glottal stop ʔ, so حديقة sounds like ḥadīʔa.
• جميلة is often pronounced jmīle in everyday speech, though a fuller jamīle may also be heard.

So the written sentence is standard-looking, but the spoken Levantine pronunciation is a bit different.

Because Arabic usually leaves out the present-tense verb to be.

So:

• الحديقة جميلة = The garden is beautiful

There is no separate word for is in this kind of present-tense sentence.

If you want past or future, then a verb appears:

• الحديقة كانت جميلة = The garden was beautiful
• الحديقة رح تكون جميلة = The garden will be beautiful

Because حديقة is a feminine noun, and adjectives in Arabic agree with the noun they describe.

So:

• حديقة is feminine
• therefore the adjective must also be feminine: جميلة

If the noun were masculine, you would use جميل instead.

This is grammatical gender, so it is about the word’s grammar, not whether the thing is literally female.

Because here جميلة is the predicate of the sentence, not part of a noun phrase.

• الحديقة جميلة = The garden is beautiful

But if you say:

• الحديقة الجميلة

that means:

• the beautiful garden

So in الحديقة جميلة, the second word is not the beautiful. It is simply beautiful.

This is one of the most important differences for learners.

They look similar, but they do different jobs.

• الحديقة جميلة = a full sentence
  The garden is beautiful

• الحديقة الجميلة = a noun phrase
  the beautiful garden

A quick way to think about it:

• no الـ on جميلة -> sentence with is
• الـ on both words -> noun + adjective together

Because Arabic normally puts adjectives after the noun.

So Arabic says the equivalent of:

• garden beautiful

not:

• beautiful garden

This is true in noun phrases:

• الحديقة الجميلة = the beautiful garden

And in your sentence, جميلة also comes after الحديقة because Arabic is saying:

• The garden
  • beautiful

which functions as The garden is beautiful.

In everyday pronunciation, final ة is usually not pronounced as a strong t.

In Levantine, it often sounds like:

• -a in some words
• -e in many others

So here you will often hear something like:

• ḥadīʔa
• jmīle

The t sound can reappear in more formal Arabic or when the word is followed by certain endings or constructions.

No, not in Levantine.

In very formal Standard Arabic, this sentence could be read with case endings as:

• الحديقةُ جميلةٌ

But in Levantine, speakers do not use those endings in normal speech.

So for Levantine, just say:

• الحديقة جميلة
• pronounced something like il-ḥadīʔa jmīle

It is correct and understandable, and people do use it. But in very casual speech, many Levantine speakers might more naturally say حلوة for pretty / nice / beautiful.

So both are possible:

• الحديقة جميلة = The garden is beautiful
• الحديقة حلوة = The garden is pretty / nice

A rough feel is:

• جميلة = a bit more standard or explicit
• حلوة = very common and conversational

A very common way is:

• الحديقة مو جميلة
• or الحديقة مش جميلة

Both mean The garden is not beautiful.

Which negative word is more common depends on the region and speaker, but مو and مش are both very useful Levantine forms to know.