1) Keith certainly can't be held responsible for the accident -> Keith can't be held responsible for the accident.
2) The children themselves are not in any way to blame for the disaster -> The children themselves are not to blame for the disaster.
3) The existence of extraterrestrial is not confirmed by the report -> The existence of extraterrestrial is not confirmed in the report.
4) I was never shown how to operate the machinery -> I was never shown how to operate the machinery.
5) He never suspected that she was a witch -> He never suspected that she was a witch.
6) There has never been a time when the English language was not in a state of change -> There has never been a time when the English language was not in a state of change.