What is one reason for using a silent 'e' at the end of a word?

The use of a silent 'e' at the end of a word primarily serves to lengthen the preceding vowel sound. When a word ends in a silent 'e', it indicates that the vowel before it should be pronounced with an elongated sound. For example, the word "kit" becomes "kite" when 'e' is added; the 'i' changes from a short vowel sound to a long vowel sound. This phonetic rule helps distinguish between similar words that differ only in the presence of the silent 'e' and provides crucial information about pronunciation and meaning.

The other options do not accurately reflect the purpose of the silent 'e.' Doubling consonants, indicating past tense, or specifying proper nouns are not functions associated with the addition of a silent 'e' at the end of words.