Expressing exclamation in Arabic is done using a special style called (أسلوب التعجب). The particle used in this style is (ما), and it should be followed by the form (أفعل) of the appropriate adjective, e.g.

الشارع واسع.

“The street is wide.”

ما أوسع الشارع!

“How wide the street is!”

It should be noted that the (أفعل) form does not change whether the subject is masculine, feminine or plural.

البنت جميلة.

“The girl is beautiful.”

ما أجمل البنت!

“How beautiful the girl is!”

العرب كرماء.

“The Arabs are generous.”

ما أكرم العرب!

“How generous the Arabs are!”

The noun that follows the (أفعل) form can be substituted by a pronoun suffix, e.g.

البنت جميلة، ما أجملها!

العرب كرماء، ما أكرمهم!

Can you make exclamation statements about the following sentences?

الجو بارد.

الولد طويل.

Here is a very nice video to illustrate exclamation, suggested by Josef: 

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