I just learned that は is pronounced the same as わ ("wa"), instead of "ha" when it's used as a topic marker. But I couldn't properly find information about the grammatical rules in place to decide when to write わ or は in sentences. Could anyone explain to me when should I use one or the other?
I believe the example below is correctly using は, but why?
Thanks in advance.
PS.: I just noticed after the first answer that I got really confused when I was studying the subject, people don't use わ as a topic marker in sentences. But it seems that it's too late and now I'm not allowed to delete the question anymore.