在英语学习过程中，许多学习者会疑惑：“knowledge” 是可数名词吗？ 答案是：通常情况下，“knowledge” 是一个不可数名词。
✅ 正确理解：knowledge（知识） 在绝大多数语境中为不可数名词，不能直接加复数形式 “knowledges”，也不能与不定冠词 “a” 连用（如 “a knowledge” 通常是错误的）。
为什么 “knowledge” 是不可数名词？
“Knowledge” 表示一种抽象概念——人类通过学习、经验或研究获得的信息总和。这类抽象名词（如 information, advice, furniture）通常被视为不可数。
✅ 正确：She has a lot of knowledge about history.
❌ 错误：She has many knowledges about history.
❌ 错误：He gave me a useful knowledge.
❌ 错误：She has many knowledges about history.
❌ 错误：He gave me a useful knowledge.
特殊情况：何时可以“量化” knowledge？
虽然 “knowledge” 本身不可数，但我们可以通过以下方式表达“某种知识”或“某方面的知识”：
- 使用 “a piece of knowledge”（一条知识）
- 使用 “areas/fields/types of knowledge”（知识领域/类型）
- 使用 “deep/extensive/little knowledge of...” 等形容词修饰
✅ He shared a valuable piece of knowledge with us.
✅ Different cultures have different types of traditional knowledge.
✅ She has extensive knowledge of classical music.
✅ Different cultures have different types of traditional knowledge.
✅ She has extensive knowledge of classical music.
注意：在极少数学术或哲学语境中，有人使用 “knowledges” 来强调不同文化或体系下的“多元知识体系”（如 Indigenous knowledges），但这属于专业用法，日常英语中应避免。
常见错误总结
- ❌ I learned a new knowledge today. → ✅ I learned a new fact today.
- ❌ She has three knowledges. → ✅ She has knowledge in three areas.
- ❌ Do you have any knowledges about AI? → ✅ Do you have any knowledge about AI?
小测试（自测）
判断以下句子是否正确：
- His knowledge of physics is impressive.
- She gained many knowledges during her travels.
- This book contains useful pieces of knowledge.
答案：1. 正确；2. 错误；3. 正确