you can use strpos to check if a letter is in a string, but to search an array you'll need to use a foreach...
foreach($vowels as $vowel)
{
$firstLetterIsAVowel = (strpos($stringsArrayString, $vowel) === 0 ? true : false);
}
if ($firstLetterIsAVowel)) {
echo $stringsArrayString . "aWord" . "< >";
}
else {
echo "**".substr($stringsArrayString, 1) . "$stringsArrayString[0]" . "aWord" . "< >";
}
note the use of === instead of == as strpos returns false if not found, and 0 == false. I did it like that because that was your question, but i'd rather check if $stringArrayString[0] is a vowel like this...
in_array ( $stringArrayString[0] , $vowels)