If a string doesn't end in `s`, `x`, `ch`, `sh` or if it doesn't ends in a vowel, then I need to add a 's'. This works for tell and eat but doesn't work for show. I am not able to figure out why.

This is the code I wrote:

```
if not re.match(".*(s|x|ch|sh)",s):
    if re.match(".*(a|e|i|o|u)",s):
        s = s+'s'
        return s
else:

    return s

```