We have known him for a week.(改为一般过去时) Mr Wang has kept goin

We have known him for a week.(改为一般过去时)
We knew him a week ago.
我们一周前认识他的.
Mr Wang has kept going to work on foot for twenty years.(同义句)
Mr Wang has kept walking to work since twenty years ago.
王先生从20年前起就走路上班了.