You specification is rather vague. Using the word split is likely to make a Perl user think you want to split your string into possibly more than two parts. The following does that trick:

my $string = join ' ', 1 .. 30;
my @parts = $string =~ /((?:\S*\s?){1,11})/g;

pop @parts;
print ">$_<\n" for @parts;
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Prints:

>1 2 3 4 5 6 7 8 9 10 11 <
>12 13 14 15 16 17 18 19 20 21 22 <
>23 24 25 26 27 28 29 30<
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