in reply to
$eng =~ s/you/ya/ig;
$eng =~ s/aren't you/int'cha/ig;
Note that the second line above will never do anything since "aren't you" will become "aren't ya" before the line is executed. Similarly, "army" will never be changed as it will become "arme" before the relavent regex gets run.
That first error jumped out at me but looking closer it looks like you've accounted for most of those types of errors. Just a few minor bugs still left (ain't that always true). (:
(but my friends call me "Tye")