One way could be through their distinct personality traits. Maybe one twin is more outgoing while the other is more reserved.
In stories, twins can be differentiated by their interests and hobbies. For example, one twin loves reading and the other loves sports. Or, you could show that they have different dreams and goals.
You can tell twins apart in stories by giving them different physical features like a unique birthmark or hairstyle. Also, their clothing choices or accessories can be different.
In the fanfiction, perhaps Harry has a special ability or spell that helps him tell the twins apart. Or it could be as simple as the twins deliberately giving him some secret signs or signals to help him differentiate. Another possibility is that Harry notices differences in their magical auras. Each person's magical aura can be unique, and Harry, being observant, might have detected this difference between the twins.
It could be as simple as their voices. Maybe one has a slightly deeper or higher pitch than the other. Hermione, being intelligent and detail - oriented, pays close attention to these nuances and is thus able to tell them apart.
The unique concept of Harry being able to do what others find difficult is interesting. It gives a fresh perspective on his relationship with the twins.
It shows her attention to detail. Hermione is known for being observant, and this is another example of that trait.
One way is to pay attention to the direction of writing. Some Asian scripts write from top to bottom, while others go from left to right. Also, the complexity and simplicity of the characters can give you hints.
You can look at the art style. Different artists might have distinct ways of drawing characters and scenes.
It could be that Percy pays attention to their individual interests within the fanfiction. If one of them has a particular hobby or passion that the other doesn't share as strongly, that could be a clue for Percy. Also, perhaps their interactions with other characters differ slightly. Fred might be more likely to tease a certain character, while George has a different way of relating to that same character.
You can look at the art style. Chinese comics often have a more diverse range of styles, while Japanese comics usually have distinct character designs and panel layouts. Korean comics might feature more detailed and realistic art.
In some fanfics, Harry might be able to tell Fred and George apart by their different interests within the story. For example, Fred could be more interested in potion - making experiments that are a bit on the wild side, while George is more into the business side of their joke shop plans. So when they talk about their hobbies or future plans, Harry can distinguish between them. Also, their sense of humor might be slightly different. Fred might crack a certain type of joke more often, like those related to magical creatures in a really absurd way, while George prefers jokes about Hogwarts professors. Through these nuances in their personalities, Harry is able to tell them apart.
The Kray Twins story is a dark chapter in London's history. Ronnie and Reggie Kray started their criminal careers at a young age. They were very violent and used intimidation to get what they wanted. They had connections everywhere, from the seedy underbelly of London to the glamorous world of showbiz where they rubbed shoulders with stars. However, their actions couldn't be overlooked forever. The law finally got hold of them. Their trial was highly publicized, and their sentencing put an end to their reign of terror in London's East End.