Modern Standard Arabic Comparatives and Superlatives

Arabic uses one pattern, af3al, for both "bigger" and "the biggest". In comparisons it doesn't change for gender or number.

Making the comparative

Take the three root letters of the adjective and put them into a_ _a_:

"Than" is min

• القاهرةُ أكبرُ من الإسكندريةِal-qaahiratu akbaru mina al-iskandariyyatiCairo is bigger than Alexandria.
• هي أطولُ منهhiya atwalu minhuShe is taller than him.

The superlative

Put the comparative before an indefinite singular noun (an iḍāfa):

• أكبرُ مدينةٍakbaru madiinatinthe biggest city
• أفضلُ طالبٍ في الصفِّafdalu taalibin fii as-saffithe best student in the class

Or use it with al- after a noun. In this use it does agree, with a special feminine form fu3laa:

• الطالبُ الأكبرُat-taalibu al-akbaruthe oldest student
• البنتُ الكبرىal-bintu al-kubraathe eldest girl

Adjectives without the pattern

Longer adjectives, colours and participles use akthar (more) or ashadd (more intensely) + an accusative noun:

• أكثرُ أهميةًaktharu ahammiyyatanmore important
• أشدُّ حُمرةًashaddu 7umratanredder