Dogs are easy to take care of. Food is run out .为什么第二句没有of.

Question

the sweater is too expensive to buy.为什么不加it. 关于及物动词和不及物动词有点晕晕的

Answer 1

1.及物动词它们不可以单独用，后面必须跟宾语。
不及物动词；它们可以单独用，如果后面想接宾语，动词后面必须加上介词。
run out of 是及物动词
2.the sweater就是buy的宾语，加it 就重复了。

Answer 2

如果要of的话，那就要写成：Food ran out.
run out of 是及物动词，后面要跟名词。例如：We run out of food.

the sweater就是buy的宾语，提前了。加it 就重复了。
祝你学习进步！
望采纳，谢谢！追问

那为什么The sweater is so expensive that I can't afford to buy it.这里要加IT

追答

呵呵，这是因为这个事有一个状语从句啊，从句也好，主句也罢，一定要有主语、谓语、宾语。而前面的那句话只有一个句子啊！
明白了吧，同学？
再如：The shoes are too small to wear.
The shoes are so small that I can't wear them.
祝你好运！

本回答被提问者采纳