my $string = 'bla bla [[en:English]][[de:German]][[ga:Irish]] bla bla';

if (my @matches = ($string =~ m/\[\[(?<lang>en|de|ga):(.+?)\]\]/g)) {
    say 'matches';
    say 'matches: ', Dumper(\@matches);
    say 'minus  : ', Dumper(\%-);
    say 'plus   : ', Dumper(\%+);
}