trouble什么时候不可数，什么时候可数?
"It is a pity to give you so much trouble.”"Life is full of small troubles."这两个句中.trouble为何在前句中不可数，而在后句中可数?
这一问题涉及某些抽象名词的数的不同用法。一般说来，如trouble, kindness, anxiety, joy, friendship, sympathy, pity, curity等均属于抽象名词，是不可数的，但当它们的词义经转化或带有修饰成分时，可以“具体化”并被不定冠词修饰或加上复数后缀I.s1.。试比较下列各对句子:
1.This was another example of their lack of experience.(经验)
2.I've had some very disturbing experiences.(经历)
1.It is a pity to give you so much trouble.(麻烦)
2.Life is full of small troubles.(烦心的事)
1.He was filled with joy.(欢乐)
2.My children are a great joy to me.(令人快慰的事)
此外，还需说明的是抽象名词的数的问题有如下几种情况:
1)既可用作不可数名词.又可用作可数名词，词义区别不大的抽象名词。如:
belief一a belief一beliefs;
birth一a birth一births;
hope一a hope一hopes;
change一a change一changes;
desire一a desire一desires ;
custom一a custom一customs;
habit一a habit一habits等
2)既可用作不可数名词，又可用作复数名词但有词义区别的抽象名词。如:
damage(损害)-damages(赔偿费)
advice(忠告)-advices(消息，报告)
regard(尊敬.关心)-regards(问候)
pity(怜悯，同情)-pities(不幸)
sympathy(同情)-sympathies(慰问信)
delicacy(精美，微妙)-delicacies(山珍海味)
3)只能用作不可数名词的抽象名词。如:
abundance, astonishment, conduct, cooperation, envy, ea, information,harm, honesty, neglect, obedience, revenge等。
4)可以用作单数或复数可数名词的抽象名词。如:
answer, award, bribe, boast, ca, cry, quarrel，trick, scream, knock, mistake, example, epoch, event, accident,晒sode, earthquake等。
5)用于特定意义时常用复数形式的抽象名词。如:
riches(财富),effects(个人所有物),thanks(感谢), manners(礼貌), rituals(宗教仪式), wishes(祝愿),excess(过分行动，暴行),doings(行为)等。
本文来自金嘴巴英语：/forum/read-32271-16.html
