2. 派生法：(即通过给一个单词加前缀或后缀构成新词的方法)，如：

1) 加前缀的情况

mid + 名词，表示“中”、“中间”，如：mid-autumn

mis + 动词，表示相反的意思，如：take → mistake

re + 动词，表示动作的重复，如：retell; return

un + 介词或形容词，构成反义词，如：unhappy; unlike; unusual

a + 动词，表示状态， 如：asleep; alive

2) 加后缀的情况

动词 → 名词：invent → inventor, invention; operate → operator, operation; drive → driver; read → reader; teach → teacher; travel →traveller; visit → visitor

形容词 → 副词：careful → carefully; loud → loudly; true → truly

名词 → 形容词：sun → sunny; rain → rainy; noise → noisy; friend → friendly; Canada → Canadian; wool → woolen; danger → dangerous

动词 → 形容词：help → helpful; use → useful; enjoy → enjoyable; worry → worried; interest → interested

形容词 → 名词：different → difference; good → goodness; foreign → foreigner