This is the 20th most frequent Arabic word.
أي
"أي" means "which," "what," or "any," depending on context.
Here, 'أي' is used as an interrogative pronoun to ask for a specific choice among options.
أي كتاب تريد أن تقرأ؟
Which book do you want to read?
In this sentence, 'أي' is used as an indefinite pronoun to indicate any unspecified choice.
هنا تضع أي شيء تحتاجه.
You can put anything you need here.
In this context, 'أي' is used as an explanatory conjunction to provide clarification or elaboration on a preceding statement.