Question

When I was a small boy,I had often sat for hours playing with the few toys I had.这道改错题错在哪？

NO.2：Sixteen years of teaching school makes an experienced educator out of a timid girl.这道改错题怎么改呢？
NO.3：Before I came,I imagined college would be a paradise that I could relax after the three stressful years of high school.又错在哪呢？

求英语大师详解！

Answer 1

When I was a small boy,I had often sat for hours playing with the few toys I had.这句里的had要去掉，前后两句没有先后关系，也可以改成一个would often sit，表示“过去常常”。

NO.2：Sixteen years of teaching school makes an experienced educator out of a timid girl谓语动词要改成has made.这不是一般事实，而是陈述一个已经发生的事情，要用现在完成时态。

NO.3：Before I came,I imagined college would be a paradise that I could relax after the three stressful years of high school这个谓语动词可以改成had imagined，这动作发生在I came之前，也可以不改的，因为Before这词已经清晰地表明了时间的先后关系。
还有a paradise that 里的that要改成：where / in which，先行词a paradise 是表示地点的，而定语从句里刚好缺少地点状语。

Answer 2

When I was a small boy,I（ had 改为 would）often sit for hours playing with the few toys I had.（would do 表示 过去习惯性动作，这句是时态错误）
Sixteen years of teaching school（ makes 改为 has made，用现在完成时，表示对现在造成的影响或结果） an experienced educator out of a timid girl.
Before I came,I （had， imagined 这个动作发生在came之前，所以用过去完成时）imagined college would be a paradise（最好将 that 改为 where，关系副词在句中作状语）I could relax after the three stressful years of high school.

Answer 3

1. When I was a small boy,I had often sat for hours playing with the few toys I had.
had 去掉，因为这里不用过去完成时，主句与从句是同个时段的事情
2. Sixteen years of teaching school have made an experienced educator out of a timid girl.
在这句中是想要陈述一个“结果”吧，所以用了现在完成时
3. I had imagined college would be a paradise that I could relax after the three stressful years of high school.
这里应该用过去完成时吧，因为是在“before i came “表示的是“过去的过去”
仅供参考

Answer 4

When I was a small boy,I often sat for hours playing with the few toys I had.
Sixteen years of teaching school HAVE MADE an experienced educator out of a timid girl.
Before I came,I HAD imagined college would be a paradise that I could relax after the three stressful years of high school.

主要是时态方面的，不是大师，仅供参考