useful后加什么词性
useful用作形容词后面加名词
It is a useful book and, what is more, not an expensiveone.这是有用的书，更难得的是不贵。
The book contains much useful information.这本书包含了许多有用的资料。
John always tries to cultivate people who are useful tohim.约翰经常设法和对他有用的人结交。
也可以放在句尾，作表语成分
例句
The book contains much useful information.这本书包含了许多有用的资料
In business a poker face can be very useful.生意场上，不动声色会非常有用。
\"For heaven\'s sake!\" Dot expostulated. \"They\'re cheap and they\'reuseful.\"“拜托!”多特反驳道，“它们又便宜又管用