词性转换类型有: (1)v.-n.动词转化为名词, post-postage mail-mail weigh-weight advise-advice (2)v.-n.-a.动词转化成名词-形容词 act-actor / actress-active change-change-changeable (3) v.-a.-ad.-n.动词转化成形容词,副词,名词 fill-full need-necessary-necessarily interest(v. / n.) interested /interesting (4)n. a. n. a.名词转化为形容词 person personal ( 个人的; 私人的 ) fun funny (5)n. pl. n. pl.名词转化为名词复数 gentleman gentlemen human humans (6)a. ad. a. ad.形容词转化为副词 possible possibly probable probably (同是转为同一词性,为什么后面转的是不同的,有什么规律?应什么时候加什么)