The power "そう"

そう, for our purposes today, means, "That's right" or "That's so" (the latter being an easy way to remember)

Construction: 
arrow This useful word is used in various idiomatic ways. It is best to learn each as an example by heart.

そうです。
sou desu
Yes, that is right.

そうですか?
sou desu ka?
Is that so?; Really?; You don't say?

そういえば・・・
sou ieba
Now that you mention it; Speaking of that...

そう考えると
sou kangaeru to
Seen from that light; Thinking like that; From that point of view

そうしたら
sou shitara
If you do it that way...