▲英语完全可以说 if not for…，根据情况可视为 if it hadn’t been for…或if it were not for…的省略形式。比如《柯林斯英语词典》在介词词条就有如下用法介绍：

For is used in conditional sentences, in expressions such as “if not for” and “were it not for’, to introduce the only thing which prevents the main part of the sentence from being true.

If not for John, Brian wouldn’t have learned the truth. 要不是因为约翰，布赖恩也不可能知道真相。

The earth would be a frozen ball if it were not for the radiant heat of the sun. 如果没有太阳辐射的热量，地球就会变成一个冰球。

She might have forgotten her completely had it not been for recurrent nightmares. 要不是因为反复做噩梦，她可能已经把她彻底忘了。

▲上面的 If not for John, Brian wouldn’t have learned the truth. 就相当于 If it hadn’t been for John, Brian wouldn’t have learned the truth.