An effective language learning program should ideally avoid explaining grammar rules, because that is not what you really want to know.  Explanations if given, should be stated as simply as possible. The best way to learn is by looking at the written word whilst at the same time, listening to it.   After doing this several times, the clear underlying patterns that identify isiXhosa as an African language will emerge, thereby enabling you to formulate your own rules.  Sufficient repetition is therefore your key to success.