有一种条件句叫做修辞性条件句Rhetorical conditional clauses。这种条件句采用真实条件句的形式，但实际表达的是强烈的陈述意义。有以下二种类型：

1 主句的内容显然是荒谬的，不可能是真实的，所以if从句的内容也不可能是真实的。

If they're Irish, I'm the Pope. ['Since I'm obviously not the Pope, they're
certainly not Irish.']
If you believe that, you'll believe anything. ['You certainly can't believe
that.']
If she doesn't get first prize, she's no daughter of yours. ['She certainly
will get first prize.']

2 如果if从句的内容是真实的，那么主句的内容也就是真实的。if 从句位于主句后。

He's ninety if he's a day. ['If you'll agree that he's at least a day old,
perhaps you'll take my word that he's ninety.']
The package weighed ten pounds if it weighed an ounce. ['The package
certainly weighed ten pounds.']
The painting must be worth a thousand dollars if it's worth a cent. ['The
painting must certainly be worth a thousand dollars.']