Since we have no information about the 'a little friend short story' other than its title, we can only make assumptions. The main character is likely to be the 'little friend'. This could be a young child, perhaps a boy or a girl. There may be other characters like a wise old man or woman in the neighborhood who gives advice to the little friend. Or there could be a group of children who are friends with the main character and they all go on adventures together, sharing joys and sorrows.
I don't know as I haven't read 'the little friend story'. But it could be a little boy or girl as one of the main characters, and their little friend which might be another child, an animal, or a fictional being.
In the 'false friend short story', the main character is often the victim of the false friend's actions. This character is usually trusting and naive at the start. The false friend is the key antagonist. They may seem friendly and charming on the surface but are hiding their true selves. Additionally, there may be a sidekick or confidant of the main character who might notice something strange about the false friend earlier on and try to warn the main character, adding an extra layer of drama to the story.
Since I don't know the specific story, it could be two friends, perhaps named John and Tom. John could be the one in need and Tom could be the helper.
Since I don't have access to the 'an old friend short story', I can't say for certain. But usually in such a story, the main characters would be the old friends themselves. There could also be secondary characters like family members or mutual friends who play a role in their relationship, either supporting or causing some sort of friction between the two main friends.
The main characters are likely the little friends themselves. They could be kids with different personalities and interests.
I would assume that the main characters are the two friends. One is the protagonist, the person whose perspective we are seeing the story from, and the other is the friend who is no longer in their life as closely. There might also be some secondary characters who play a role in the events that led to the friendship changing, like other mutual friends or family members who influenced the situation.
The main characters might include the person who first wields the little knife. This could be someone with a unique background or skill. There could also be a character who is in search of the knife for some important reason, like it holds the key to a long - lost treasure or it has the power to break a curse. Additionally, there could be a group of characters who are affected by the actions related to the little knife, for example, a community where the knife has some symbolic meaning.
As I don't know the 'little birds short story', I can't say for sure who the main characters are.
The main characters are the three bears (papa bear, mama bear, baby bear) and Goldilocks.
The little mermaid is obviously a key character. She is the one whose journey we follow. The human prince is the object of her love. He is a noble figure that the mermaid admires from afar and then tries to be with. And the sea witch is a very important character too. She is the one who enables the mermaid's transformation but also puts her in a very difficult situation with her strict conditions.