employ the simplest SELECT statement to see the restrictions, then use subquery

Orc doesn't start with an "e" or a "t". :P The problem is in your code.

Test 2

['dog', 'goose', 'orc'] should equal ['dog', 'goose']

Test 3

['dog', 'goose', 'elephant', 'tiger', 'orc'] should equal ['dog', 'goose', 'elephant', 'tiger']

what's the problem? works as expected in pycharm

I'm not familiar with PHP, but I looked at the docs and the problem you seem to be having is that PHP sort() directly changes the array you're trying to sort, instead of returning it. It returns true when the array has been sorted successfully and false when the function has run into a problem and thus was not able to sort the array. Hope this helps. Reminder -- you can always google problems you have, and docs for specific languages are available online, too.