Koreans use it to express strong approval or happiness about something.
Yes. "정말 좋아요 (jeongmal joayo)" is polite and enthusiastic. You can also say "좋아요 (joayo)" casually.
You can say "That's really great" — 정말 좋아요 (jeongmal joayo).
정말 좋아요 means "That's great / Really good." 정말 (jeongmal) = really, 좋아요 (joayo) = good/great - polite. Common enthusiastic expression when hearing good news, seeing something nice, or someone achieves something.
1. Good news: React positively.
2. Approval: Show enthusiasm.
3. Celebration: Congratulate.
That's great! Congratulations!
That's great. Excellent. (Formal)
That's great! Amazing! (Casual)
Wow, that's great. Awesome!
• 대박 (daebak) - Amazing / Wow
• 멋져요 (meotjyeoyo) - It's cool / Awesome
• 최고예요 (choegoyeyo) - It's the best