­y/­ty/­ity honest→honesty　　　　　 诚实

difficult→difficulty 困难

cruel→cruelty 残酷；残暴

safe→safety 安全

disable→disability 无能；伤残

responsible→responsibility 责任 　　

名词、动词转换为形容词　 　　

　　[全析考法]

　　单句语法填空

　　1．(2018·全国卷Ⅰ)Running is cheap, easy and it's always ________ (energy)．

　　解析：energetic　根据句子结构可知，此处应该使用与其前的cheap, easy相同形式的形容词energetic作表语。

　　2．(2018·全国卷Ⅱ)According to the World Bank, China accounts for about 30 percent of total ________ (globe) fertilizer consumption.

　　解析：global　此处和total一起修饰名词短语fertilizer consumption，意为"全世界的化肥总消耗量"，故用其形容词形式global作定语。

　　3．(2018·6月浙江高考)The obvious one is money; eating out once or twice a week may be ________ (afford) but doing this most days adds up.

　　解析：affordable　根据语境可知此处作表语，所以要用形容词形式。

　　4．(2014·全国卷Ⅱ)There were many people waiting at the bus stop, and some of them looked very anxious and ________ (disappoint)．

　　解析：disappointed　和前面的anxious并列，表示人的内心活动，应使用­ed形式的形容词，此处表示"他们中有些人看起来既焦虑又失望"。

　　[谨记规则]

后缀 例　词 ­able accept→acceptable　　 　　可接受的

comfort→comfortable 舒适的

fashion→fashionable 时髦的

suit→suitable 合适的

reason→reasonable 有道理的