$re = '/((?:\s*\w+)+|(?:\s*[\u0590-\u05FF]+)+?(?=\s?[A-Za-z0-9!?.]))/i';
$str = 'so היי all whats up אתכם אתכם test היי?';
$subst = "<span>$1</span>";
$result = preg_replace($re, $subst, $str);
echo "The result of the substitution is ".$result;
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