Two meanings:
Seems like
Recipe: adjective/verb + そう
- create a new (な) adjective by grafting そう onto an adjective/verb
e.g., 高い服 → 高そう服
I heard
Recipe: statement + そう + (だ・です)
- completes a statement (+ だ・です)
- does not change any adjective/verb
Examples
- 美味しい → 美味しいそうです
- 綺麗(だ) → 綺麗だそう