function maybePluralize(singular, countable, plural) {
  plural = plural || `${singular}s`

  if (countable && countable.length === 1) {
    return singular
  } else {
    return plural
  }
}
Returns a string that is either the singular or the plural form of a word,
depending on the length of the countable parameter.

@param {string} singular - Singular form of the word
@param {string[]} countable - Array of values you want to count
@param {string} plural - Plural form of the word
@returns {string} Singular or plural form of the word