1. Adverb (fukushi), Noun

   in the first place; to begin with; from the start; originally; ab initio

   Usually written using kana alone

   そもそもなぜ鳥は移動するのだろうか。

2. Conjunction

   after all; anyway; actually; well, ...; ... on earth (e.g. "what on earth?"); ... in the world (e.g. "why in the world?")

   Usually written using kana aloneused when bringing up something already mentioned

3. Noun, Noun which may take the genitive case particle 'no'

   beginning; start

   Usually written using kana alone

Also written 抑々【そもそも】somosomo、抑抑【そもそも】somosomo