I forgot to include the following statements, too. Thank you very much for your help!
1) A narrator can be external to (?) the story and talk about events he has not taken part in.
2)A third-person narrator refers to the characters using the third person voice.
3)A character (and not "the"?) can be
flat or round.
4) A flat character can be easily recognized (is simple to recognize? is wrong) since he is based on a single psychological trait.
5) Instead (or on the contrary, on the other hand) a round character
6) The description of human beings as dingy shaped is used by the poet to refer to the alienation.
7) The wind was bodiless. He had no body and no feet (no body or feet?) to bind him.
8) The wind's fingers produce a music similar to (can you use "like") the tremolous (vibrating? is wrong) sound blown into the glass.
9) The wind quickly (?) tapped at her door and left her alone again.
10) Can you say: "In this poem there are two important (significative) figures of speech: a simile and a metaphor. Or is it correct to say (the poet uses two figures of speech, namely a metaphor and a simile/two figures of speech occur in the poem?
No problem! Here are the revised statements:
1) A narrator can be external to the story and talk about events they have not taken part in.
2) A third-person narrator refers to the characters using the third-person voice.
3) A character can be flat or round.
4) A flat character can be easily recognized since they are based on a single psychological trait.
5) On the contrary, a round character...
6) The poet uses the description of human beings as "dingy shaped" to refer to alienation.
7) The wind was bodiless. It had no body or feet to bind it.
8) The wind's fingers produce a music similar to the trembling sound blown into the glass.
9) The wind quickly tapped at her door and left her alone again.
10) In this poem, there are two important figures of speech: a simile and a metaphor.