Well, in many such fanfictions, it could be that Harry shows some unusual behavior like extreme shyness or fear around certain people. For example, he might flinch when an adult gets too close too quickly. This could be a sign that makes others start to suspect something is wrong. Another key event could be that he has unexplained injuries that he tries to hide, and when someone finally notices these, it sets off the chain of events towards uncovering the abuse.
In some versions, Harry might have nightmares that are so intense that they draw the attention of those around him. He could be shouting in his sleep about being hurt or scared. People close to him, like a young playmate or an observant teacher at a pre - Hogwarts school, might pick up on this. They could then start to piece together the signs of abuse from his other behaviors, such as being overly withdrawn during the day or having a fear of going back home.
Often, in this type of fanfic, a friend or a kind neighbor might notice that Harry is always alone and looks malnourished. His clothes might be dirty or ill - fitting. This visual cue can be a big factor in the discovery of the abuse. Maybe the neighbor starts to offer Harry food, and when he wolfs it down hungrily, it makes the neighbor suspect that he's not being taken care of properly at home. This then leads to further investigation and the discovery of the abuse.
The discovery of the abuse might make Harry more empathetic towards other students who have had difficult pasts at Hogwarts. He could become a sort of advocate for those who are bullied or mistreated. Also, it could affect his relationship with his teachers. Some teachers, when they learn of his past abuse, might be more lenient or offer more support, which in turn helps him grow and develop at Hogwarts.
One key element could be the exploration of Harry's early life traumas. Since he was abused, it might focus on how that affected his character development. For example, it could show his mistrust of adults or his fear of certain situations. Another element could be the discovery of his magic in the midst of this difficult situation. Maybe he unknowingly uses magic to protect himself from the abuse, which then draws the attention of the wizarding world.
In some fanfiction, Harry's abuse before Hogwarts is shown through his physical appearance. He may be depicted as undernourished, with bruises that he tries to hide. For example, he might always wear long - sleeved shirts to cover up the marks on his arms.
One possible answer could be that in some fanfictions, it might be Dumbledore who first notices the signs of abuse. He might see Harry's withdrawn behavior or the way he flinches at sudden movements, which are typical signs of an abused child. This could lead to Dumbledore taking immediate steps to remove Harry from that situation and bring him into the wizarding world earlier than in the original story.
It shows how the abuse affects Harry's behavior. He might be constantly on edge, always looking over his shoulder. This is a sign of the trauma he's endured. The fanfiction may also explore how he has trouble trusting people, which is a common result of trauma.
One example could be 'The Young Harry's Ordeal' where the author delves into how the wizarding world reacts to a de - aged Harry and the signs of abuse that start to surface. Another might be 'Harry's Regression and Revelation' which focuses on Harry's internal struggle as a de - aged character dealing with the abuse he had endured before but is now seeing it in a new light as he is younger and more vulnerable.
The discovery might also lead to new friendships and alliances for Harry. The goblins have their own network, and they could introduce Harry to other characters who can help him in his journey. It might also cause a rift between Harry and those who were supposed to protect him but failed, like the Dursleys or some Hogwarts staff if they were aware of the abuse.
In some versions of this fanfiction, it could be Neville. He also had a difficult family situation, so he might be more attuned to signs of distress in Harry. Maybe he notices Harry's worn - out clothes that are too big for him, which could be a sign of neglect, and then starts to piece together that something is wrong at the Dursleys'.
One consequence could be that Harry becomes withdrawn. He's so used to the abuse that he doesn't trust people easily. He might have nightmares often, reliving the moments of abuse. For instance, if Vernon has hit him before, he could have flashbacks in his sleep.
Hermione would probably be the first to notice the signs of abuse. She'd be very methodical about it, perhaps making a list of all the things that seem off. Ron, on the other hand, would be more impulsive. He might get angry right away when he realizes what has been happening to Harry. Dumbledore, being the wise figure, would likely start to put plans in motion to protect Harry and also to deal with the source of the abuse.