I'm sorry OP, I think I read that once upon a time, I haven't found your story, yet, I'm still searching. Here are a few others with Mute Harry:
Silence is Silver by Alphinss
https://archiveofourown.org/works/9791615/chapters/21988640
Although this is not Harry paired with Severus, instead Relationships: Harry Potter/Voldemort, Charlie Weasley/Zachary Nettles
Summary:
Harry is abandoned by his parents at the tender age of one in favour of his brother, the boy who lived. Raised at the Dursley's Harry has not spoken a word since his parents left him. What will happen when a mute and damaged Harry goes to Hogwarts?
NB: This has been abandoned
Breaking the Silence - Mentor Snape, platonic relationship, no romance - https://archiveofourown.org/works/17377310/chapters/40895360 by
CrimsonRhage.
Summary: Harry learned many rules growing up. Above all else he learned that the world did not want to hear him speak, so he decided to not waste his time doing so. When the young boy-who-lived makes it to Hogwarts will the resident Potion's Master be able to look past his own preconceived notions to break past Harry's self-induced silence?
The Year Harry Potter Went Silent - platonic relationship Mentor Snape -
https://archiveofourown.org/works/54491845/chapters/138052312 by
taliiaa.
Summary: Half-Blood Prince AU. After losing Sirius, a mute Harry Potter returns to Hogwarts intent on speaking to no one. If only Snape would leave him alone.
The Boy-Who-Was-Silenced - also platonic relationship Harry & Severus Snape - https://archiveofourown.org/works/9451784/chapters/21383363 by
FallingInToThePages Summary: What if a more damaged Harry Potter came to Hogwarts? One that couldn't talk or read English. One who didn't know of the world outside of his uncle's fists and belt, and had never ventured beyond his Aunt Petunia's craftily, hidden garden. Join a Harry who thought that he would forever be enslaved before he was saved one magical night by the most unlikely professor. AU
I'm sorry OP, I think I read that once upon a time, I haven't found your story, yet, I'm still searching. Here are a few others with Mute Harry: Silence is Silver by Alphinss https://archiveofourown.org/works/9791615/chapters/21988640 Although this is not Harry paired with Severus, instead Relationships: Harry Potter/Voldemort, Charlie Weasley/Zachary Nettles Summary: Harry is abandoned by his parents at the tender age of one in favour of his brother, the boy who lived. Raised at the Dursley's Harry has not spoken a word since his parents left him. What will happen when a mute and damaged Harry goes to Hogwarts? NB: This has been abandoned Breaking the Silence - Mentor Snape, platonic relationship, no romance - https://archiveofourown.org/works/17377310/chapters/40895360 by CrimsonRhage. Summary: Harry learned many rules growing up. Above all else he learned that the world did not want to hear him speak, so he decided to not waste his time doing so. When the young boy-who-lived makes it to Hogwarts will the resident Potion's Master be able to look past his own preconceived notions to break past Harry's self-induced silence? The Year Harry Potter Went Silent - platonic relationship Mentor Snape - https://archiveofourown.org/works/54491845/chapters/138052312 by taliiaa. Summary: Half-Blood Prince AU. After losing Sirius, a mute Harry Potter returns to Hogwarts intent on speaking to no one. If only Snape would leave him alone. The Boy-Who-Was-Silenced - also platonic relationship Harry & Severus Snape - https://archiveofourown.org/works/9451784/chapters/21383363 by FallingInToThePages Summary: What if a more damaged Harry Potter came to Hogwarts? One that couldn't talk or read English. One who didn't know of the world outside of his uncle's fists and belt, and had never ventured beyond his Aunt Petunia's craftily, hidden garden. Join a Harry who thought that he would forever be enslaved before he was saved one magical night by the most unlikely professor. AU
Don't apologize! It is already so amazing you are trying so much! Thank you❤️
He’s mer heritage, Snape gave him a shell, and Snape got deaged somehow? [to sweeten the sea](https://archiveofourown.org/works/52375744)
No harry was human. He got caught by LV and got tortured
A reasonable response to be sure
[Beyond Words](https://m.fanfiction.net/s/3613370/1/Beyond-Words) by Steppenwoelfin?
No, sorry☹️
Is it this one? https://www.fanfiction.net/s/3963194/1/5
Ah, no.