Help me improve my vocab.
A friend told me that if I want to learn a new word and remember it, I should use it seven or eight times.
If someone could check my sentences below and put a yes or no next to each one to indicate which are correct, that would be great.
1. 这是一张伤心的脸。
2. 你怎么这么伤心?
3. 他看起来很伤心。
4. 我刚看一本伤心的书。
5. 孩子好像很伤心。
6. 今天是你的生日,为什么是伤心的?
7. 你觉得高兴还是觉得伤心?
Thanks for your time and help.
谢谢