Question

把错语改正确了

他是直到昨天才改变主意的．

误：Not till yesterday he changed his mind．

正：

Answer 1

答案：Not until yesterday did he change his mind．
解析：

not until位于句首时，主句的主语和谓语要用倒装语序．如：Not until recently did I know what he meant by doing so．我是在最近才知道他这样做的用意的．