'da broke何意？

有一读者问： 有这样一句话：

(1)If I'da broke my neck I'd be dead.

如何解释’da broke?

这是不规范的美国口语。I'da broke=I would have broken。 would have broken在美国口语中常等于表与过去相反的虚拟式had broken。再如：

(2)If you would have come sooner you could have helped us.