Is it A or An? An easy way to remember, is that if it's a consonant word, use A, if it's a word that begins with a vowel, use An. An or a worksheets. Printables for an or a. Words commonly confused worksheets focusing on when to us a and when to use a. Is it a or is it an? Find out how to use a and an in sentences. These worksheets are for 3rd and 4th grade students or advanced younger students. Great ESL worksheets and vocabulary worksheets.