suppose、supposing作连词引导条件状语从句

suppose本来是动词，supposing本来是现在分词，但它们有时可用作连词，引导条件状语从句，其意为“假若”“如果”等；此时主句通常为疑问句。如：

Suppose your father saw you, what would he say?

你父亲要看见你，他会怎么说？

Suppose they did not believe him, what would they do to him?

要是他们不相信他，他们会对他怎样？

以上2例摘自《汉英大词典》

Supposing he can’t come, who will do the work? 假使他不能来，这工作谁做?

Supposing he does not come, shall we go without him? 如果他不来，是不是不带他去?

Suppose you were given a chance to study in America, would you accept? 假如给你一个到美国学习的机会，你会接受吗?

Suppose [Supposing] (that) we miss the train, what shall we do? 假如我们误了火车，我们将怎么办?

注意，suppose用作连词引导条件状语从句时，它必须置于主句之前，但supposing用作连词引导条件状语从句时，则可置于主句之前，也可以置于主句之后。如：

We'd love to come and see you on Saturday, supposing I don't have to work that day. 我想星期六来看你，假若那天我不上班的话。