sixteen-year-old 可以做名词吗
我知道一般sixteen-year-old是形容词,sixteen-year-olds是名词.
既然sixteen-year-olds是名词（16岁的人们）,而且是复数,比如：Sixteen-year-olds are not allowed to drive.
那么可以设想sixteen-year-old是它的单数形式吗?比如：A sixteen-year-old is not old enough to drive.