1. crack a smile 展顏微笑，莞爾一笑

Definition: to smile, especially when you do not feel like smiling.

The man was willing to do anything to make his wife crack a smile. (為了讓他的妻子展顏微笑，他愿意做任何事情。)

2. laugh a hearty laugh/laugh heartily 放聲大笑，開懷大笑

Definition: to laugh loudly and uncontrollably

Upon hearing that he had won the lottery, the man laughed heartily. (知道自己中獎了，這個男人開懷大笑。)

3. force a smile 強作歡顏

Definition: to smile even though you feel sorrowful or unhappy

At the funeral, he forced a smile for anyone who offered condolences. (在葬禮上，他強顏歡笑面對前來吊唁的人。)

4. a saccharine smile 諂笑，諂媚的笑

Definition: a smile designed to please others

When he talks to his boss, he puts on a saccharine smile. (他跟老板說話的時候，滿臉都是諂媚的假笑。)

5. smile bitterly 苦笑

Definition: to smile when you have no choice or can do nothing to help

The student smiled bitterly when his teacher caught him copying his homework. (抄作業被老師抓到后，這個學生滿臉苦笑。)