事故发生一小时以后，我开始镇静下来。

正：An hour after the accident, I was starting to feel calmer.

误：After an hour of the accident, I was starting to feel calmer.

《薄冰英语惯用法词典》在 after 词条中指出：说“某事件的若干时间以后”可用“若干时间 + after + 事件”来表示。例如：

It happened two years after the incident. 这事发生在事变两年以后。