What and where is the function that implements the tr/// operator? Be as precise as you can.
How does the way Perl executes a program different from the way the Unix shell executes one? Contrast shell, Perl, Java and C.
Without looking, where do you think the Perl_keyword function would be? Find it, and explain what it does.
Several files in the Perl source tree are generated from other files. Look at all the *.pl files in the root of the Perl source tree, and find out what each file is responsible for generating, and from what sources. Be extremely careful when looking at embed.pl.