>perl -wMstrict -le
"use v5.14;
 use warnings;
 ;;
 while (<>) {
     chomp;
     if (m/(?<WORD>\b\w*a\b)(?<EXTRA>.{0,5})/) {
     say qq{Word contains '$+{WORD}'};
     say qq{Extra characters after Word are '$+{EXTRA}'};
     } else {
     say qq{No Match: |$_|};
     }
 }
"
I saw Wilma yesterday
Word contains 'Wilma'
Extra characters after Word are ' yest'
^Z