按照名词的单复数形式,抽象名词可分四种情形:
A.只能用作不可数名词的抽象名词:
advice(建议)，information(信息),
news(新闻),happiness(幸福)，sadness（悲伤）
anger(愤怒)，progress(进步)，
harm(伤害),damage(损坏)，
envy(嫉妒)，work(工作)，
honour(荣誉)courage(勇气)，
health(健康),wealth(财富),
assistance(援助)，bravery(勇敢)，
knowledge(知识),honesty(诚实),
importance(重要性)，ugliness(丑陋)，
good(善良)，behaviour(行为) ，furniture 家具
homework(家庭作业) information（消息）
B.既可用作不可数名词,又可用作可数名词的抽象名词,在这两种用法中,词义不发生本质变化:
hope/hopes(希望) fear/fears(恐惧),
belief/beliefs(信念),condition/conditions(条件)
science/sciences(科学)，success/successes(成功),
study/studies(学习)
既可用作不可数名词,又可用作可数名词的抽象名词,在这两种用法中,词义发生本质变化:
success和failure成功的人（或范例）或失败的人（或范例）
pleasure令人愉快的人或事（或范例）；money-moneys(monies)金额，某笔款（项）
water-waters（某一江、河、湖、海的）水域; （某个国家的）领海，海域; 不明朗（或未知的、困难、危险等）局面
This species is found in coastal waters around the Indian Ocean.
在环印度洋沿岸的海域有这一物种。
We were still in British waters.
我们仍在英国的领海上。
in international waters
在国际海域
The conversation got into the murky waters of jealousy and relationships.
交谈进入到爱妒交织的复杂话题。
The government has warned of stormy waters ahead.
政府已告诫说，以后的局势将很严峻。
difficulty（难点，难处，难题，严重的困难,困难，困境）
We've run into difficulties/difficulty with the new project.
我们在这项新工程中遇到了难题。
The way ahead is strewn with difficulties.
前面的道路布满艰难险阻。
The public was more forgiving of the president's difficulties than the press and fellow politicians.
公众比报界和总统的政界同事更能体谅他的难处。
The bank is in difficulty/difficulties.
这家银行处境困难。
The company has got itself into difficulties.
公司本身陷入了困境。
She had got into financial difficulties.
她陷入了财务困境。
It was a time fraught with difficulties and frustration.
这是一个充满困难和挫折的时期。
Every job has its difficulties and frustrations.
每个工作都有困难和令人懊恼之处。
He got into difficulties while swimming and had to be rescued.
他游泳时遇险，只好靠人营救。
You have to admit that you are, in fact, in difficulties.
你不得不承认，你事实上是陷入了困境。
I've had some difficulties, but they were nothing compared to yours.
我遇到了一些困难，但与你的困难比起来就算不上什么了。
His increasing financial difficulties forced him to take desperate measures.
不断增加的经济困难迫使他采取了铤而走险的办法。
You soon get used to the little difficulties.
你很快就会习惯这些小小的不便了。
Our jobs overlap slightly, which sometimes causes difficulties.
我们的工作略有重叠，所以有时引起一些困难。
The difficulties in her way merely strengthened her resolve.
她所遇到的困难只是让她更加坚定。
Cases of breathing difficulties increase in lockstep with air pollution.
呼吸困难的病例随空气污染的加剧而增加。
Several pupils were designated as having moderate or severe learning difficulties.
几名学生被认定有一定或严重学习困难。
C，只能用作可数名词的抽象名词:
idea(想法)，remark(意见,评论,话),
situation(局势),answer(回答)，
case(情况)，event(事件)，
mistake(错误)statement(声明)
D，只以复数形式出现的抽象名词(其单数往往另有含义):
goods(商品),manners(礼貌),
riches(财富),wishes(祝愿),
congratulations(祝贺),letters(文学)，
spirits(情绪)，thanks(感谢)
