1.School start at nine o'clock.改错并语法说明 2.He is a five-years-old boy.
问题描述：
1.School start at nine o'clock.改错并语法说明 2.He is a five-years-old boy.
答
1.School starts at nine o'clock.School 是单数形式,后面的动词start要加s
2.He is a five-year-old boy.five-year-old 是个定语,year不需要加s