You need a look ahead assertion. In this case a negative look ahead assertion (?!to\b|from\b): 

use strict;
use warnings;

while (<DATA>) {
  print "Matched $_" if /train times (?!to\b|from\b)\w/;
}
__DATA__
train times to xyz
train times from xyz
train times including xyz
train times tomorrow xyz

[download]

Prints:

Matched train times including xyz
Matched train times tomorrow xyz

[download]

Update: fixed missing \b bug

DWIM is Perl's answer to Gödel

In reply to Re: negate pattern match by GrandFather
in thread negate pattern match by Anonymous Monk

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