Also, be sure that you conceptually understand what the finished data structure will look like. Every "element of" an array, hash, or list is "a single element," but that "single element" can be a reference to anything-at-all ... which, in turn, can have more-than-one reference to it at a time. Perl's syntax is especially generous in this regard, to make it very easy to manipulate these structures and for Perl to "do the right thing." Carefully read over the perldoc's about "references" and about its approach to memory management. Until you have a crystal-clear mental picture of that, you're going to continue to feel very confused ... especially if you are used to working with other languages that support "strong typing."