string pluralize(string $str, int $num[, int $mode)

$str - the string to "pluralize"

$num and $mode - determine what to do

If $mode is 0 (the default), then returns $str if $num is 1, else returns $str+"s" or (if v14.00+) $str+"es" if $str ends in "s"

If $mode is 1, then returns $str+"y" if $num is 1, else returns $str+"ies"