Thank you very much for your corrections. I still have a few doubts on thr following sentences.

1) You should have referred to Defoe's novels when analyzing the features of 18th-century novels.
2) 18-century novels have the following features./The main features of 18-century novels are as follows. (are they both possible?).
3) As I told you several times, you must use sentence connectors such as “first, second, or one feature is..” when listing your ideas and not introduce them with the letters of the alphabet.
4) You merely re-wrote what’s on the photocopy I gave you without changing a single word.
5) His point of view coincides with that of the main character/with the main character’s/ with the main character one (is a mistake?).

1. Remove the hyphen between 18th and century.

2. Correct the first part of this. Either phrasing will work. Be sure to end with a colon since what you put afterward will be explaining this part.

3. OK

4. OK

5. The first two alternatives work; the third one doesn't.

1) The sentence "You should have referred to Defoe's novels when analyzing the features of 18th-century novels" is grammatically correct and conveys the idea that using Defoe's novels as a reference would have been beneficial when analyzing the features of 18th-century novels.

2) Both "18th-century novels have the following features" and "The main features of 18th-century novels are as follows" are grammatically correct and convey the same idea. Whether you choose to use one or the other depends on your personal style and preference.

3) The sentence "As I told you several times, you must use sentence connectors such as 'first, second, or one feature is..' when listing your ideas and not introduce them with the letters of the alphabet" is grammatically correct. It emphasizes the importance of using appropriate sentence connectors instead of introducing ideas with letters of the alphabet when listing them. This adds clarity and coherence to your writing.

4) The sentence "You merely re-wrote what's on the photocopy I gave you without changing a single word" is grammatically correct. It implies that the person being addressed simply copied the content from the photocopy without making any modifications or alterations.

5) The phrase "with the main character one" is not grammatically correct. It should either be "His point of view coincides with that of the main character" or "His point of view coincides with the main character's." Both variations are acceptable and convey the idea that his perspective aligns with that of the main character.