Ordinal Numbers

Ordinal numbers (first, second, third…) are adjectives in Arabic. From third on they are built on the pattern fāʿil from the number's root: ثالث (third) from ثلاثة, رابع (fourth) from أربعة, عاشر (tenth) from عشرة. First is irregular: الأول / الأولى, and second is الثاني / الثانية.

• Like every adjective, the ordinal comes after the noun and agrees with it in gender: الدرس الثالث (the third lesson), المرة الثالثة (the third time).
• It takes ال when the noun is definite, also when the noun has a possessive ending: زيارتي الأولى (my first visit).
• The feminine adds ة: الخامس → الخامسة, العاشر → العاشرة.
• Dates use the masculine ordinal with اليوم: اليوم الخامس من مايو (the fifth of May).