1. Anybody didn't come. (Not OK)
2. Somebody didn't come. (OK) (i.e., A certain person didn't come.)
Sentence 1. is odd because 'any' has a wide semantic reference. For example, Please take any one of these pens. You have a wide choice. To make 'any' specific, or to narrow down its semantic field of reference, a negative is added, like this,
3. Didn't anyone come?
4. No one came.
5. Not any one (person) came.
1. I can't tell "Anybody didn't come." from
2. "Not any one (person) came."
I am looking forward to your explanatios...
You're welcome. :D
In 1., "Anyone" is the subject. The verb is "come" and it's negated by "didn't". Sentence 1. means, an unknown group of people within an unknown group (i.e., Anyone) didn't come. It's rather non-specific, wouldn't you agree? Q: Who came? A: Anyone. What does that mean? Should someone, a known person, group come?
In 2., "person" is the subject". The word "not" negates the "any one". It means, not a single person.