
twenty-year-old“二十岁的”,此词组相当于一个形容词用,只能作前置定语,即只能放在被修饰的词的前面。如He'satwenty-year-oldsinger.twentyyearsold“二十岁”,此词组只能作后置定语或表语如Heissingeroftwentyyearsold.(后置定语)Heistwentyyearsold.(表语)

twenty-year-old“二十岁的”,此词组相当于一个形容词用,只能作前置定语,即只能放在被修饰的词的前面。如He'satwenty-year-oldsinger.twentyyearsold“二十岁”,此词组只能作后置定语或表语如Heissingeroftwentyyearsold.(后置定语)Heistwentyyearsold.(表语)