Question

eight years old和eight-years-old到底有什么区别，单词选项怎么选两个

Answer 1

eight years old 作表语,意思是"8岁".如: He is eight years old.他8岁了.

没有eight-years-old这个词,正确的写法是:eight-year-old 作定语,意思是"8岁的";如:
He is an eight-year-old boy.他是一个8岁的男孩.

Answer 2

an eight years old和an-eight -year-old 没区别，第二个只不过是通过连词符将所有词组成了一个合成形容词而已。

但你的题中 ， 是eight-years-old 这种写法是错的，选 第一个。如果去了s,写成eight-year-old就对了。那样的话，两个都对

Answer 3

单项选择要选：eight years old
单词中间用连字符连接时，不要用复数。
正确的是：eight-year-old.

Answer 4

How old is.