そう (sō) means “so, that way” | MotiTan Japanese Dictionary

More examples

そうしてください。sō shi te ku da sa i

Please do it that way.

「明日も休みですか」と聞かれて、「そうです」と答えます。asu mo yasu mi de su ka to ki ka re te sō de su to kota e ma su

When asked whether tomorrow is a holiday too, I answer, "That's right."

Connects an action or judgment to a previously identified manner or state instead of stating it again.

こうkō: In the manner or state indicated by the speaker's words or actions.
どうdō: Asks about the manner or state of an action or situation.

話題になっている事柄を受け、その内容や状態に沿って。wa dai ni na tte i ru koto gara o u ke so no nai yō ya jō tai ni so tte

そう (sō, "so; that way") comes from historical さう (sau, "that way"), whose au vowel sequence changed into the long o sound in modern Japanese.

The repeated form そうそう (sō sō, "exactly; that's right") shows strong agreement with a point just made and is common in friendly conversation.