الانطباع الأول جيد.

A careful MSA pronunciation is:

al-inṭibāʿ al-awwal jayyid

A few notes:

• الانطباع = al-inṭibāʿ
• الأول = al-awwal
• جيد = jayyid

In fully vocalized Arabic, it would usually be written:

الانطباعُ الأوَّلُ جيِّدٌ

In normal unvocalized writing, those short vowels are simply left out.

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

Arabic often uses a nominal sentence:

• الانطباع الأول = the subject
• جيد = the predicate

So الانطباع الأول جيد literally looks like:

the first impression — good

But in natural English, that means:

The first impression is good.

If you wanted was, Arabic would usually use كان. For example:

كان الانطباع الأول جيدًا = The first impression was good.

Because in Arabic, adjectives normally come after the noun they describe.

So:

• الانطباع الأول = the first impression
• literally: the impression the first

This is different from English, where adjectives usually come before the noun.

Yes. الأول here is an ordinal adjective, meaning first.

It describes الانطباع, so the phrase is:

الانطباع الأول = the first impression

This is not a separate noun phrase like the impression of the first. It is simply a noun plus its adjective.

Because Arabic adjectives agree with the nouns they describe in definiteness as well as gender and number.

Here:

• الانطباع is definite: the impression
• so the adjective must also be definite: الأول = the first

That is why you get:

الانطباع الأول

not:

الانطباع أول

In Arabic, if the noun is definite, its adjective is normally definite too.

No. It is not an iḍāfa.

It is a noun + adjective phrase.

Why?

Because in an iḍāfa, the first noun does not take الـ unless it is inherently definite in some other way, and the second word is a noun, not an adjective. Here, الأول is functioning as an adjective and matches الانطباع in definiteness.

So:

• الانطباع الأول = noun + adjective = the first impression

not an iḍāfa.

Because it is the predicate of the sentence.

The structure is:

• الانطباع الأول = the subject
• جيد = the comment about it

So Arabic naturally says:

The first impression good

which English expresses as:

The first impression is good.

This is a very common Arabic sentence pattern.

Because جيد is the predicate here, and predicates in this kind of sentence are usually indefinite.

So:

• الانطباع الأول جيد = The first impression is good

If you said الجيد, it would sound different in meaning and structure, more like the good one or a marked/emphatic expression, not the normal simple statement.

So the plain, natural form is:

الانطباع الأول جيد

Because it matches الانطباع, which is a singular masculine noun.

Arabic adjectives normally agree with the noun they describe or refer back to in:

• gender
• number
• definiteness

Since الانطباع is masculine singular, the predicate appears as masculine singular too:

جيد

If the noun were feminine, you would expect a feminine form such as جيدة.

In fully vocalized formal Arabic, you would usually have:

الانطباعُ الأوَّلُ جيِّدٌ

All three words are in the nominative here:

• الانطباعُ: subject of the nominal sentence
• الأولُ: adjective matching the subject
• جيدٌ: predicate of the nominal sentence

In everyday reading and most ordinary writing, these endings are usually omitted, so you simply see:

الانطباع الأول جيد

Yes, but that would usually happen when the noun is indefinite.

For example:

• انطباع أول would mean a first impression in a very literal grammatical sense, though this exact phrase is less common in normal usage than the definite one.
• الانطباع الأول means the first impression

So in this sentence, because the noun is definite, the adjective is also definite:

الانطباع الأول

That is the expected and correct pattern.