He was 13 two years ago.两年前他13岁They were at home last weekend.上周末他们呆在家She was at her grandpa's yesterady.昨天她在爷爷家I was very thin three years ago,but now I am fat.三年前我很瘦,但现在...要有时间词那句话没有时间词，第一句 two years ago, 第二句 last weekend 第三句 yesterday 第四句 three years ago 第五句 last year,第六句 six years ago第七句 yesterday第八句 just now第九句 two years ago第十句 three years ago第十一句 two hours ago比如说Grandma was making breakfast at 7:30.中的7：30就是时间词。还比如说We were reading books from 3:30 pm to 5:00 pm.中的3:30和5:00就是时间词只能说你理解的时间词太狭隘了