心(xīn)

 
字形：
古体“心”字是人或动物心脏的象形，“心”字的本义就是心脏。但是中国古人又常常把心视作感觉、思维的器官，说“心之官则思”，认为思想、感情、意念等都发自人心，“心”也用来表示“思想、感情、意念”  等相关的意义。
The original form of the character "心" was the image of a man’s or an animal’s heart, and it means the "heart" from the beginning. Ancient Chinese used to believe that people feel and think with their hearts, and therefore "心" is also used to express meanings relating to thought, feeling and mind.
 
字义：
heart
 
组词：
中心（zhōngxīn）：center
心情（xīnqíng）：mood
担心（dānxīn）：worry
小心（xiǎoxīn）：careful
信心（xìnxīn）：confidence
心脏（xīnzàng）：heart
 
例句：
Jīntiān fā gōngzī le, xīnqíng hěn hǎo.
1、今天发工资了，心情很好。
I am in good mood today because I get salary.
Rènhé shíhou dōu yào duì nǐ zìjǐ yǒu xìnxīn.
2、任何时候都要对你自己有信心。
Be confident to yourself at anytime.
Tā yī ge rén qù tán hézuò,wǒ yǒudiǎnr dānxīn.
3、她一个人去谈合作，我有点儿担心。
She went to the client to talk about the cooperation alone. I’m a little worried about that.