基数词+单数名词+形容词构成合成形容词。如:一个五岁的男孩a
five-year-old
boy;一座800米长的桥an
800-metre-long
bridge;女子400米接力girls'400-metre
relay
race。16-year-old是形容词,比如说a
16-year-old
boy,但是16
years
old一般作表语,比如the
boy
is
16
years
old.
2.
基数词和名词构成合成词时误用复数。
My
teacher
is
a
twenty
–five-years-old
girl.
〔解析〕本句子是考查:基数词+单数名词+形容词构成的合成形容词的用法。中间的名词用单数形式,所以把twenty
–five-years-old改为twenty-five-year-old。
希望对你有所帮助。