This is the 33rd most frequent Japanese word.
そう
"そう" means "so," "that way," or "like that" depending on context.
Here, "そう" is used as an affirmative response, confirming something previously said or asked.
そうです。
That's right.
Here, "そう" is used to express an assumption or prediction about what is likely to occur based on observable evidence.
空が暗くなってきた、雨が降りそうだ。
The sky is getting dark; it looks like it’s going to rain.
In this sentence, "そう" is used to introduce one's own thought or impression about the situation.