在英语中，"afford" 是一个及物动词，它后面应该接 to do而不是 doing。以下是一些关于 "afford to do" 的例句和用法说明：
表示“承担得起做某事”
She can afford to travel around the world.
They can afford to wait for another two hours.
表示“买得起做某事”
He can't afford to buy such an expensive car.
How can you afford to do something like this？
表示“经受得起做某事”
I can't afford to miss this opportunity.
综上所述，正确的用法是 "afford to do sth."，而不是 "afford doing sth."。因此，在需要表达“承担得起做某事”或“买得起做某事”时，应该使用 "afford to do" 这个搭配。
