Would fate be a theme or a subject. Most websites would just list fate as a theme. However, i learned before that a subject is what a book talks about and a theme is like a lesson. So what would fate be?

Fate itself is simply a topic or an angle for the playwright or the storyteller or the novelist.

Read through the themes listed and explained on this webpage:
http://www.sparknotes.com/shakespeare/romeojuliet/themes.html
Do you see how themes are usually stated in phrases or clauses?

You're right in thinking that themes are often the lesson (or a lesson) that the author wants his/her readers or audience to "get" by means of the story.

Determining whether fate would be considered a theme or a subject can be a matter of interpretation and may vary depending on the context. However, I can provide you with some guidance on how to approach this question.

In literature, a subject generally refers to the topic or main idea of a literary work. It is what the book talks about on a surface level. On the other hand, a theme is a broader, underlying message or lesson that the author wants to convey through the story. It represents the deeper meaning or insight that can be inferred from the text.

When it comes to fate, it can be argued that it falls into both categories. As a subject, fate can often be a central focus of a story. Characters might struggle against or embrace their predetermined destinies, and the narrative may revolve around the consequences of fate. In this sense, fate can be seen as the topic being explored.

On the other hand, fate can also function as a theme. It can raise questions and provoke thoughts about determinism, free will, and the role of destiny in human lives. By examining the choices characters make in the face of fate, the narrative can delve into larger ideas about the nature of existence, human agency, or the inevitability of certain events.

Ultimately, whether one considers fate a theme or a subject may depend on how the concept is approached and developed within a specific literary work. It is essential to analyze the context, the author's intent, and the overall message conveyed through the exploration of fate within the story.