“four”怎样换一个字母使其成为另一个单词？

four可以把f换成h ，这样单词就变成hour（小时）。

hour   英 [ˈaʊə(r)] 美 [aʊr]          小时、钟头、时间、时刻、固定时间。

例句

1. They waited for about two hours.

   译文：他们等了将近2个小时。

2. Getting there would take hours.

   译文：大约需要花费很长时间。

3. The gathering storm had made the day even darker than was usual at this hour.  

   译文：即将到来的暴风雨使得天空看起来比平时这个时候更昏暗。

4. He recalled her devotion to her husband during his hour of need.  

   译文：他回忆起她在丈夫困难之时的忠贞奉献。 

5. Phone us on this number during office hours.  

   译文：上班时间打这个电话给我们。
   

参考资料

人教.《初中英语一年级上册》.北京：人民教育出版社，2013

把f改成y就成了your