Things I didn't like:
*You switcch between past and present tense a lot. I would suggest maybe find a editor or even have a honest friend read over your work before you publish.
*Your grammer and puntuation needs to be fixed. Once again maybe, a editor or spell-check will really help.
Things I did like;
*Your story plot (Not the Hogwarts part of course.) is very realistic and relatable. The character is worried about not fitting in everyone can understand that.:)
*Your detail is very great. Just make sure it flows all through the story. Otherwise, the readers can be caught off gaurd.
Overall, I give you a 3/5 star rating. Just fix those things.:)
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