chapter
In French, 'chapitre' is used to refer to a main division of a book, which is typically numbered or titled. It is used in similar contexts as 'chapter' in English. For example, 'J'ai fini le chapitre quatre de mon livre' translates to 'I finished chapter four of my book'.
Chapter two starts here.
This sentence is commonly used when referring to the start of a new chapter, in this case, chapter two. It implies that the previous chapter has ended and a new one is beginning.
This chapter of the book is interesting.
This sentence expresses an opinion about a particular chapter of a book being interesting. The subject of the sentence is 'Ce chapitre' (this chapter).
He forgot to read the chapter on biology.
This sentence is about someone forgetting to read a specific chapter of a book that is about biology. This may imply that the person has an obligation or intent to read it.