$re = '/\h*\b\p{Lu}\p{L}*\b/mu';
$str = 'Ещё Одно слово
hello goodbye Delete Me
Another Sentence good program
hello world The End
an iPhone
Ещё Одно слово';
$subst = "";
$result = preg_replace($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