摘要：He shouted a warning but it was too late. （他大声警告，但为时已晚。 ） [朗文当代英语词典; 警告的目的没有达到]

be late是“迟了”，而be too late是“太迟了”，其too有“过度而使企图不能成功”的否定蕴意，如

【例句1】He shouted a warning but it was too late. （他大声警告，但为时已晚。 ） [朗文当代英语词典; 警告的目的没有达到]

【例句2】The doctors did all they could, but it was too late. （医生们竭尽全力，但为时已晚。）[牛津高级学者辞典；医生救人没有实现]

【例句3】Buy now before it's too late.(现在就买，以免为时已晚。)[牛津高级学者辞典; 介词before抵消“否定意蕴”]

too late的主语可以是人，如

【例句4】Are we too late to get tickets? （我们买票是不是太晚了？）[朗文当代英语词典]

【例句5】I'm afraid you're too late to apply for the job. （恐怕你来不及申请这份工作了。）[牛津高级学者辞典]

It is too late to do也是定型句型，如

【例句6】It was too late to turn back. （时间太晚了，回不了头。 ）[朗文当代英语词典/柯林斯高级学者辞典]

【例句7】It's too late to save her now.（已经太晚了，救不了她） [牛津高级学者辞典]

【例句8】It's too late to start complaining now. (已经太晚了,现在抱怨没用了。)[剑桥高级学者辞典]

【例句9】It's getting too late to do anything today.（今天太晚了，做不来任何事。 ） [牛津高级学者辞典]

对【例句6到9】，it被理解为“时间、时机”，这与【例句1到3】中的it一致。

当然若将it is too late to do的it理解为代to do，那么【例句6到9】的语义也是说得通的，而且两种理解的语义差异不大。

您认为哪一种理解更合理呢？

来源：明日之星教育