Sonanda

[cloa513]

Forgive me if there is a thread that covers this but I am unable to find it.
I just can't find Sonan da and the definitition that my Japanese girlfriend gives for it doesn't gel with how she uses it.

[Cyclamen]

そうなんだ ("sounanda!") has a meaning which could be expressed with expressions like "that's it!!" or "oh, it's like this". It can be used in many occasions, bit always when the speaker is referring to something that has already been explained.