I checked the sentence as you told me. I included a few other sentences I need to prepare on Poe.

1) In July 1814 the couple fled to France and later moved to Switzerland, where they rented a house on the banks of Lake Geneva.
2) Under the influence of her husband she was inspired to write her novel “Frankenstein”, which was published anonymously in 1818.
3) He is confined to (also "in") a cottage.
4) Poe can be regarded as the first theorist on short stories.
In his Philosophy of Composition he worked out a theory about the Unity of effects, inspired by Schlegel and Coleridge, which he applied not only to his poems but to his tales as well.
5) He claimed that the main intent of a writer is not to develop ideas, but simply to create a "single effect" which must be conceived beforehand and to which everything must tend.
6) In other words, all the incidents that make up a story or a tale must be invented to work out this effect, which is to strike the reader so as to keep him virtually prisoner inside the work itself.
7) Fear, for example, is (was) often the effect Poe chose for many of his short stories and every word was carefully chosen to create an effect of fear within the mind of the reader.

1. comma needed

2. comma needed -- novel's title is indicated how?

3. "confined to a cottage" (not "in")

4. Is that the title of a book or an article or what?

No capital on "unity"

comma needed

5. OK

6. OK

7. was
comma needed

Great! It seems like you have prepared a few sentences on Edgar Allan Poe. Here's an analysis of each sentence:

1) In July 1814 the couple fled to France and later moved to Switzerland, where they rented a house on the banks of Lake Geneva.
- This sentence portrays the movement of the couple to France and then Switzerland. The year mentioned is 1814.

2) Under the influence of her husband, she was inspired to write her novel "Frankenstein", which was published anonymously in 1818.
- This sentence highlights the influence of her husband on the author of "Frankenstein" and the fact that the novel was published anonymously in the year 1818.

3) He is confined to (also "in") a cottage.
- This sentence suggests that someone is restricted or limited to staying inside a cottage.

4) Poe can be regarded as the first theorist on short stories.
- This sentence attributes the title of the first theorist on short stories to Edgar Allan Poe.

5) He claimed that the main intent of a writer is not to develop ideas, but simply to create a "single effect" which must be conceived beforehand and to which everything must tend.
- This sentence discusses Edgar Allan Poe's claim about the primary purpose of a writer, emphasizing that it is to create a single effect that should be planned in advance and that all elements of the writing should contribute towards achieving that effect.

6) In other words, all the incidents that make up a story or a tale must be invented to work out this effect, which is to strike the reader so as to keep him virtually prisoner inside the work itself.
- This sentence explains further the concept from the previous sentence, stating that all the events in a story or tale should be constructed to serve the purpose of creating an effect that captivates the reader, holding them captive within the narrative.

7) Fear, for example, is (was) often the effect Poe chose for many of his short stories, and every word was carefully chosen to create an effect of fear within the mind of the reader.
- This sentence exemplifies the specific effect that Poe frequently aimed to create in his short stories, which is fear. It emphasizes Poe's meticulous selection of words to evoke a sense of fear in the reader's mind.

I hope this analysis helps you in your preparation on Poe! Let me know if there's anything else I can assist you with.