I ate a peach and an apple. Therefore, an is used because it is acting as an article proceeding a word beginning with a vowel sound . Ferns make good house plants. Teachers do not receive high salaries. Leaves falling off trees in autumn make me sad.
Many politicians are lawyers .
His grandparents were farmers . The is used to indicate a noun that has already been identified and is therefore specific. I ate an orange and a peach. The orange and the peach both were very sweet. The flower in the vase is red.