Select the correct sentence:

Answer: An apple fell from the tree.

Rule: Use "an" before words that begin with a vowel sound (a, e, i, o, u).

• Why the correct sentence is "An apple fell from the tree.": "apple" begins with a vowel sound, so the correct indefinite article is "an." "the tree" specifies a particular tree.

• Why "A apple..." (as in some options) is wrong: "a" before "apple" is incorrect because of the vowel sound; it should be "an."

• About "The apple fell from a tree.": This sentence is grammatically correct, but it has a different meaning—it refers to a specific apple that fell from an unspecified tree. The chosen correct sentence uses "an" for an unspecified apple and "the" to indicate a particular tree.

• Quick tip: Decide whether the noun is being referred to generally or specifically, and choose "a/an" (unspecified) or "the" (specified). Use "an" before vowel sounds.