I only realized how dangerous the situation had been when I got home.
=> Only when...............................

He only thought about having a holiday abroad after he retired.
=> Only after...............................

If I had realized what would happen, I wouldn’t have accepted the job.
=> Had I..................................

The facts were not all made public until later.
=> Only until.......................

His brother had rarely been more excited.
=> Rarely had.......................

A sleeping dog was lying under the table.
=> Under.....................

We only began to see the symptoms of the disease after several months.
=> Only after......................

He didn’t finish his work until the bell rang.
=> Not until...........................

I had only just put the phone down when the boss rang back.
=> Hardly had...................

He had hardly left the office when the telephone rang.
=> No sooner...................