Extract words from string with preg_match_all

Question

I\'m not good with regex but i want to use it to extract words from a string.

The words i need should have minimum 4 characters and the provided string can

Answer 1

$string = Sus azahares presentan gruesos pétalos blancos teñidos de rosa o violáceo en la parte externa, con numerosos estambres

$words = explode(' ', $string);
echo $words[0];
echo $words[1];

and so on