★for作介词，表价格时，可理解为“当作”之意，后接表示“金钱”或“三餐”之类的名词：
I bought it with ten dollars.(╳)
I bought it for ten dollars.(√)
该句子的实际句意是“这个东西我是10块钱买的”，亦表示“我买了它当作10块
★实战演练：
What can you buy for one dollar?
你一块钱能买什么？
Today these paintings are sold for large sums of money.
今天这些画卖价甚高。
What would you like for breakfast?
你早餐想吃什么？
I usually have sandwiches for lunch,but rice for dinner.
I bought it with ten dollars.(╳)
I bought it for ten dollars.(√)
该句子的实际句意是“这个东西我是10块钱买的”，亦表示“我买了它当作10块
★实战演练：
What can you buy for one dollar?
你一块钱能买什么？
Today these paintings are sold for large sums of money.
今天这些画卖价甚高。
What would you like for breakfast?
你早餐想吃什么？
I usually have sandwiches for lunch,but rice for dinner.