Lets not forget the 'certainly':

if ( /see the \d brown foxes\. they are \w+ fast\./ ) {
  # do something
}
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or with capturing (like ikegami pointed out)

my ($count, $word);
if (($count, $word) = /see the (\d) brown foxes\. they are (\w+) fast\
+./) {
  print("There are $count foxes. Let's go hunting!$/");
}
[download]