Correlatives are among the most challenging concepts in Esperanto. It takes some study and effort to get the hang of them, but once you do it all makes sense.
I am reading, La Tuta Esperanto, by Henrik Seppik, and I found a great graphical presentation of the correlatives. They make a lot more sense this way.
I created this graphic based on the illustration in Seppik’s book. Please let me know what you think about it!