1. 基本含义
knowledge 是一个不可数名词，表示“知识；了解；知晓”。它通常指通过学习、经验或教育获得的信息、事实或技能的总和。
She has a wide knowledge of painting and music.
她对绘画和音乐有广博的知识。
2. 语法特点
- ✅ 不可数名词：不能直接加复数，也不能与不定冠词 a/an 连用。
- ❌ 错误示例：a knowledge / knowledges
- ✅ 正确表达：a piece of knowledge / areas of knowledge
He shared a valuable piece of knowledge with us.
他和我们分享了一条宝贵的知识。
3. 常见搭配
- broad / deep / extensive / general / practical knowledge（广博/深入/广泛/一般/实用的知识）
- acquire / gain / obtain / share knowledge（获取/获得/分享知识）
- knowledge of [something]（对……的知识）
- common knowledge（常识）
- scientific / technical / cultural knowledge（科学/技术/文化知识）
4. 经典例句
- His knowledge of history is impressive.
- It’s common knowledge that smoking is harmful to health.
- Students are encouraged to apply their knowledge in real-life situations.
- Without basic computer knowledge, it’s hard to find a job nowadays.
5. 常见错误提醒
⚠️ 很多人会误用 “knowledges”，但这是错误的！knowledge 永远不可数。
⚠️ 不要说 “I have a knowledge of French.” 应改为 “I have knowledge of French.” 或更自然地说 “I know some French.”
6. 小测验（自测）
判断以下句子是否正确：
- She has many knowledges about biology. → ❌（应为：much knowledge）
- He has a good knowledge of world affairs. → ✅（固定搭配，此处 a good knowledge 表示“相当程度的了解”）
注：虽然 knowledge 不可数，但在 “a good/excellent/thorough knowledge of...” 结构中，习惯使用不定冠词，这是英语中的特殊用法。