She memorized the key concepts of the book.

Meaning: She learned the most important ideas of the book so well that she could remember them without looking at the book.

Choice of Words: Memorized means to learn something so well that you can remember it without looking at it, key means very important or significant, and concepts are ideas or beliefs.

Alternative Expressions

The girl had the main ideas of the book in her head.

Meaning: This means that the girl has learned the most important ideas in the book and can remember them even if she doesn't have the book with her. It's like saying, The girl knows the main ideas of the book off the top of her head.

Choice of Words: Girl is a young female child. Had means to possess or own something. Main means the most important or significant part of something. Ideas are thoughts or concepts. Book is a written work that contains information or a story. Head is the part of the body that contains the brain. When you put them together, "The girl had the main ideas of the book in her head" means that the girl had learned and understood the most important parts of the book and could remember them in her mind.

The young lady knew the book's important thoughts.

Meaning: This means that the girl has learned the most important ideas in the book and can remember them even if she doesn't have the book with her. It's like saying, The young lady has a good understanding of the book's main points.

Choice of Words: Young lady is a polite way to refer to a girl or woman. Knew means to have knowledge or understanding of something. Book's shows that the book belongs to something or someone. Important means very significant or valuable. Thoughts are ideas or opinions. When you put them together, "The young lady knew the book's important thoughts" means that the girl had learned and understood the most important ideas in the book.

Related Expressions