أي

Which

Level 2

أيّ (ayyu) is the Arabic word for 'which.' It is unique because it changes its ending based on its position in the sentence and is almost always followed by a noun in the genitive case.

How It Works

The particle أيّ is a versatile tool in Modern Standard Arabic. Here are its key characteristics:

  • Case Sensitivity: It is the only question word that changes its final vowel. It appears as أيُّ (nominative), أيَّ (accusative), or أيِّ (genitive) depending on its grammatical role in the sentence.
  • The Idafa Structure: It functions as the first part of an Idafa construction. When followed by an indefinite singular noun, it means 'Which [noun]?' (e.g., أيُّ كتابٍ؟). When followed by a definite plural or dual noun, it means 'Which of the [nouns]?' (e.g., أيُّ الكتبِ؟). Notably, when followed by a definite singular noun, it typically means 'Which part of [noun]?' (e.g., أيُّ المدينةِ؟ meaning 'Which part of the city?'). The following noun must be in the genitive case.
  • Meaning 'Any': Beyond questions, it can mean 'any' or 'some kind of' in affirmative or negative statements, such as in the phrase 'بأيِّ ثمنٍ' (at any price).
  • Gender: While the masculine أيّ is common and can be used for both genders, أية is the feminine form used in more formal contexts when preceding feminine nouns. In everyday Modern Standard Arabic, the masculine form is frequently used for both.
  • Vocative Use: When using the vocative to call a noun that has the definite article, you must use أيُّها (masculine) or أيَّتُها (feminine) between the calling particle and the noun.
  • Exclamatory Use: It can be used for emphasis or exclamation to mean 'What a...!' or 'What a great...!', such as in the phrase 'أيُّ رجلٍ هو!' (What a man he is!).
  • Conditional Use: Beyond questions, it can function as a conditional particle meaning 'whichever', often followed by verbs in the jussive mood.

Examples (6)

  1. أيُّ كتابٍ مفيدٌ؟

    Which book is useful?

    Word by Word: Which book useful?

    In this nominal sentence, 'ayyu' is in the nominative case because it acts as the subject.

  2. في أيِّ مدينةٍ تسكنُ؟

    In which city do you live?

    Word by Word: In which city you live?

    Because it follows the preposition 'fī', the word changes to the genitive case 'ayyi'.

  3. أيةَ لغةٍ تتكلمُ؟

    Which language do you speak?

    Word by Word: Which language you speak?

    Here, the standard feminine form 'ayyata' is used in the accusative case because the noun 'language' is feminine and the object of the verb.

  4. يا أيُّها الرجلُ، تعالَ هنا.

    O man, come here.

    Word by Word: O which-he the man, come here.

    When calling a noun with the definite article, 'ayyuha' (masculine) or 'ayyatuhā' (feminine) must be used.

  5. أيُّهم ذهبَ إلى المدرسةِ؟

    Which of them went to the school?

    Word by Word: Which of them went to the school?

    This shows 'ayyu' attached to a pronoun suffix (-hum).

  6. سأشتري البيتَ بأيِّ ثمنٍ.

    I will buy the house at any price.

    Word by Word: I will buy the house by any price.

    In non-question sentences, 'ayyu' can mean 'any' or 'some kind of', functioning as an indefinite adjective.

Common Mistakes

  • Treating 'ay' as indeclinable.

    في أيُّ مدينة؟
    في أيِّ مدينةٍ؟

    Learners often forget that 'ay' must change to 'ayyi' after a preposition.

  • Using the nominative case for the following noun.

    أيُّ كتابٌ؟
    أيُّ كتابٍ؟

    The noun following 'ay' must always be in the genitive case because it is part of an Idafa structure.

How It Connects

Tap a pattern to see what it builds on and what it leads to.

أيLevel 2Which

Learn This First

To understand 'أي' (Which), a learner needs to know how to form an Idafa construction, as 'أي' acts as the first noun in that structure. Consequently, the learner must understand that the noun following 'أي' will be in the genitive case (majrur). Finally, the learner should be familiar with the general rule that question words in Arabic are placed at the start of the sentence.

Words in This Pattern

أي