the adjective which describes something is following the described word in defining or undefining , masculine or feminine , singular or plural So, we put ال in front of the objective when the described noun is definite eg: قابلت الرجل الكبير قابلت رجلا كبيرا قابلت رجالا كبارا قابلت الرجال الكبار I hope that I could help you, good luck with your lessons Best wishes

Adjectives agree with the nouns they modify in gender, number, case, and definitiness. Non-human masculine plurals require singular feminine adjectives. Definite nouns take definite adjectives. The prefix ال indicates that an adjective is definite.