المسرح كبير.

A careful MSA pronunciation is al-masraḥu kabīrun.

In pause, or in less formal pronunciation, you will often hear al-masraḥ kabīr.

A few pronunciation notes:

• ال is pronounced al- here, because م is a moon letter, so the l sound stays.
• ح in مسرح is a deeper, breathier sound than English h.
• كبير is pronounced kabīr, with a long ī sound.

ال is the Arabic definite article, meaning the.

So:

• مسرح = theater / theatre
• المسرح = the theater / the theatre

It is a complete sentence.

Arabic allows a very common type of sentence called a nominal sentence, which can consist of:

• a subject: المسرح = the theater
• a predicate: كبير = big

So the whole sentence means The theater is big.

By contrast:

• المسرح الكبير means the big theater

That is a phrase, not a full sentence.

In Arabic, the present-tense verb to be is usually not written or spoken in sentences like this.

So:

• المسرح كبير literally looks like the theater big
• but it means The theater is big

This is normal Arabic grammar.

If you want other tenses, Arabic does use verbs, for example:

• كان المسرح كبيرًا = The theater was big

Because here كبير is the predicate of the sentence, not an adjective inside a noun phrase.

Compare these two:

• المسرح كبير = The theater is big
• المسرح الكبير = the big theater

This is a very important distinction in Arabic:

• definite noun + indefinite adjective/predicate can form a sentence
• definite noun + definite adjective forms a noun phrase

So كبير without ال helps show that this is a sentence meaning is big, not the phrase the big theater.

In the basic word order of this kind of Arabic sentence, the subject comes first and the predicate comes after it:

• المسرح = subject
• كبير = predicate

So the normal order is:

• المسرح كبير

Also, in Arabic, adjectives usually come after the noun they describe. That is why:

• the big theater = المسرح الكبير

So whether it is a predicate or an adjective, Arabic often places this kind of describing word after the noun.

With full vowel endings, the sentence is:

• المسرحُ كبيرٌ

These endings show that both words are in the nominative:

• المسرحُ = subject of the nominal sentence
• كبيرٌ = predicate

In normal everyday writing, these short vowels are usually omitted, so you usually see:

• المسرح كبير

But learners should know that the fully vocalized form is المسرحُ كبيرٌ.

Yes. The predicate must agree with the subject in gender and number.

Here:

• المسرح is masculine singular
• كبير is also masculine singular

So they match correctly.

For example, if the noun were feminine, the predicate would also be feminine:

• المدرسة كبيرة = The school is big

Notice that in a sentence like this, the predicate agrees in gender and number, but it does not have to copy the definiteness of the subject. That is why المسرح is definite, while كبير is not.