I'm a french dude so don't judge me :)

-Children are slowly disappearing
-Children began disappearing
-Children began to disappear
-Children disappeared

Which one is the most correct form, for a short story.

All are grammatically correct. However, the first one, using the present tense, is not common for most stories.

Alright thanks !

You're welcome.

All of the forms you provided can be considered grammatically correct, but they convey slightly different meanings. Let's break them down:

1. "Children are slowly disappearing": This sentence is in the present continuous tense and suggests an ongoing action. It implies that the children are currently in the process of disappearing, possibly over a period of time.

2. "Children began disappearing": This sentence is in the past tense and indicates that the disappearance of children started at some point in the past. It doesn't specify whether the action is ongoing or if it has already concluded.

3. "Children began to disappear": This sentence is also in the past tense and conveys the same meaning as the second sentence. The only difference is the addition of the word "to" before the verb "disappear." This form is often used to emphasize the beginning of an action.

4. "Children disappeared": This sentence is in the past tense, but it describes a completed action. It suggests that children disappeared in the past, and the disappearances are now finished or no longer happening.

For a short story, the choice of the most appropriate sentence depends on the context and the desired effect you want to achieve. If you want to create a sense of ongoing suspense or mystery, options 1 and 2 might be effective. However, if you want to convey a more definitive or conclusive tone, options 3 or 4 may be better suited.

Ultimately, the decision is subjective and dependent on the narrative you wish to create.