请问下列句子表达方式有错吗?

题目

请问下列句子表达方式有错吗?
1.when they got to the middle of the river.
2.when they reached the middle of the river.
3.when they arrived to the meddle of the river.
4.when they were in the meddle of the river.
5.when they came to the meddle of the river.
6.when they swam to the meddle of the river

答案

如果这6个都是单独句子的话,那这个表达就是错误的!
特殊疑问句的句式结构是“特殊疑问词+一般疑问句”
像第一句应该改为：when did they get to the middle of the river.
接下来那些都是一样的!
如果这是作为宾语从句的话那就没问题啦,语序没错!