This is a beautiful question. Here are some golden sentences that can be used to express love and concern to girls. These sentences can be used to coquetry or express sincerity:

1. "I can't imagine life without you."

2. "You are the biggest surprise in my life."

I always miss your smile, your warmth and your kindness.

4. "You made me feel the beauty of life, and I am grateful to have you in my life."

5. "You are my moon, I am your star, and I will always accompany you."

6. "I hope I can share all your pain, so that you don't have to go through any difficulties again."

7. "You make my heart beat faster, and you make me feel happy and satisfied."

8. "I want to spend every sunrise and sunset with you and watch the beauty of the world together."

9. "I am willing to do anything for you, because you are the most important person to me."

10. "I love you not only because of your appearance and talent, but also because of your heart, your kindness and your courage."

Remember, true love lies not in words, but in actions. Show your love and care for her with actions, which is the best way to express it.