Question

The observatory was built on ______ isolated plateau far from the city lights.

• A. a
• B. an
• C. the
• D. no article

Answer 1

Answer:

B. an

The correct sentence is:

“The observatory was built on an isolated plateau far from the city lights.”

Rule: Use the indefinite article an before a word that begins with a vowel sound.

• Isolated begins with the vowel sound /aɪ/.

• Therefore, an is used before isolated.

• The noun plateau is singular and countable, and it is mentioned for the first time. Hence, an indefinite article is appropriate.