1. Theme in literary works
Theme is : The main idea or underlying meaning of a literary work.
A theme may be stated or implied.
Not every literary work has a theme.

2. There are two types of themes:
Stated Theme: is a theme that is directly told to the reader by a character in the story or the narrator.
Implied Theme: is a theme that is revealed to the reader through the actions, thoughts and feelings of the characters. This happens over the course of the plot.

3. What is the difference between the Theme and the subject?
Theme differs from the subject or topic of a literary work in that it involves a statement or opinion about the topic.
The subject is the topic on which an author has chosen to write.
The theme, however, makes some statement about or expresses some opinion on that topic.
For example, the subject of a story might be war while the theme might be the idea that war is useless.

4. Four Ways An Author Can Express Theme
Through the thoughts and feelings of the main character
Through repeated thoughts and conversations in the story
Through the actions of the characters and what the character learns
Through major events of the plot