1.Until I came back didn't my sister set out .

2. Until you work hard will you succeed one day .

3.Not until he entered the classroom did the telephone ring.

4.Seldom do I have heard such a beautiful song.

5.I can not sing the song, can not Jim sing the song either.

6.So old is he that he walks slowly.

7.Although hard did he study ，he failed the exam.

8. He spoke loudly so that he could be heard by all the people。（词句不是改为倒装）He spoke loudly (so as to be) heard by all the people.

很久没碰英语了，可能会有些错误。其中8也可填常用的in order to be。水平有限，请见谅