像下面如此的句子，because if...属什么的生肖结构？既是缘由状语从句，也是条件状语从句？这是一种什么语法现象？

He had to sTOP talking because if he’d kept on, the stuttering would have started.他不能不停止讲话，由于假如他继续下去，口吃就会发作。

I didn’t give my name because if I did I thought you might not have come.我没留下我的名字，由于假如我这么做的话，我想你可能就不会来了。

because从句本身是个主从复合句。if从句是修饰后面的句子的。将if从句移至句末就了解了。

He had to sTOP talking because the stuttering would have started if he’d kept on.他不能不停止讲话，由于假如他继续下去，口吃就会发作。

I didn’t give my name because I thought you might not have come if I did.我没留下我的名字，由于假如我这么做的话，我想你可能就不会来了。