I received a great response to the post Kid's Songs.  An English teacher friend of mine expands and clarifies my thoughts on "anybody, somebody and nobody".  I think it helps clarify what I am still struggling to understand.

Actually, there's one word to imply the words "anybody and nobody". The word is "kimse" as you've mentioned. But "somebody" is different. It means; "birisi" meaning a personality. Although, some of the dictionaries wrote "kimse" as the meaning of "somebody". But this "kimse" infers a personality which has an equal meaning with "birisi" and this is positive. In short, we use "birisi" when we teaching the meaning of the word "somebody" and when we translate a sentence to Turkish. And even "kimse" means "a person" we mostly use it as the same meaning as "nobody or anybody". It has a negative meaning unlike "birisi". only, we can't use "kimse" with a positive structure. It has a negative meaning and a negative structure in Turkish. In this respect, it is a little bit weird to see a positive structure with a negative meaning for Turkish language learners.