Globetrotter - 7:13 am on Jul 7, 2011 (gmt 0)

I'm looking for a regular expression that matches specific words in a string. I've tried a lot of options but none of them seem to work.

An oversimplified version which sort of works is

preg_match('/(ko|ao|an)/i',$output)


I would like to match the words "ko" or "ao" anywhere in a string followed by a space. Besided this match i would also match the word "'an" . If any of those two conditions is true it should return true.

At this time it sort of works but it sometimes finds a match when it shouldn't (for example if the word "cacao" is in the string it will match while it should only match on "ao some other word").