$re = '/\b(?:apple|apples|pear|pears|strawberry|strawberries|grape|grapes)\b/i';
$str = 'Today I ate an apple, then a pear, then a strawberry. This is my article and it\'s about apples and pears. I like strawberries as well though.';
preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
// Print the entire match result
var_dump($matches);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php