for my $key (keys %hash) {

##</code><code>##

for my $key (sort keys %hash) {

##</code><code>##

Global symbol "$key" requires explicit package name at ...

##</code><code>##

for my $key (sort keys %hash) {
    if ($key eq $verb) {
        $hash{$key} = $verb;
        last;
    }
}