解释 Explanation
Word formation creates new words by adding parts to existing words.
**Prefixes:** Added to beginning (change meaning):
**Suffixes:** Added to end (change word class):
**Conversion:** Same word different class (zero derivation):
**Compounding:** combining words:
Word Class Changes:
构词法通过在现有词语中添加部分来创造新的词语。
前缀：添加到词语开始（改变意义）：
- un-/in-/im-/ir-/dis-：unhappy，impossible，irregular，disagree
- re-：return，rewrite
- pre-：preview，preheat
- mis-：mistake，misunderstand
- over-：overcook，overreact
- under-：underestimate，understand
- trans-：transform，transport
- inter-：international，interact
后缀：添加到词语末尾（改变词性）：
- 名词后缀：-tion，-ment，-ness，-er，-or，-ity
- 形容词后缀：-ful，-less，-able，-ible，-ous，-ive，-al，-ic
- 动词后缀：-ize，-ify，-en
- 副词后缀：-ly，-ward，-wise
转换：同一个词语不同词性（零派生）：
- book（名词）到book（动词）
- water（名词）到water（动词）
复合词：组合词语：
- classroom，password，sunflower
词性变化：
- 名词到动词：computer到compute
- 动词到名词：develop到development
- 形容词到名词：happy到happiness
- 名词到形容词：music到musical
关键话题 Key Topics
练习题目 Practice Items
练习 Exercises
1. Which prefix means "not"?
2. Which suffix makes an adjective?
3. Complete: The opposite of "happy" is _____.
4. Which is word class conversion?
5. Complete: The noun from "develop" is _____.