Comparing "renshi" and "zhidao"

知道 vs. 认识

Similarities:

Parts of Speech: both are verbs.

Meaning: Both can mean “to know” a person. (In this sense, 知道 means “to know of” a person, but not on a personal level; whereas, 认识 means “to personally know” someone, in other words, to have had an interaction or encounter with that person).

Formal/Informal: Both can used in formal/informal settings.

Collocations: These patterns work with both 知道 and 认识: 他～你,～一个人, ～老师, ~他/她.

Example sentences (知道 AND 认识 both can be used interchangeably) : 我认识马老师。他们知道一个人，他能帮我们解决问题。小刘认识我的朋友。我知道他。他说他认识你。

Differences:

       	Parts of speech: 知道 is only a verb, whereas 认识 is mainly a verb (it can also be used as a noun, but is rather limited in usage and outside the scope of this comparison).

Meaning: 知道 means “to have knowledge of”, “to realize”, or “to become aware” of a person or something heard or said (认识 does not have this usage).

Example sentences (only 知道 can be used): 你知道你父母的生日吗？这是我第一次来中国，我不知道去哪里玩最好。你不知道他有女朋友吗？我一直生活在城市，不太知道农村人的生活习惯。你知道李老师是一名很出名的科学家吗？他知道你的意思。我真不知道怎么说。我知道这道题的答案。他知道自己是错的。老师说他不知道我们什么时候才能到重庆。

Meaning: 认识 means “to meet” (first time encounter with a person), “to have an understanding of” or “to recognize” a person, something, someone, some place, or a concept on a deep level (知道 does not have this usage).

Collocations: These patterns work only with 认识： ~你很高兴/很高兴～你, 充分~, ～路, ～地方, ～世界

Example sentences (only “认识” can be used): 你跟你老公是怎么认识的？你们先互相认识，然后我们开始讨论。那个时候我刚来上海，不认识什么本地的朋友。我不认识路。我很高兴认识你！我们认识的那一天就是他25岁的生日。我不认识那个地方。她是你朋友，你应该认识她。你们认识才几个月，就要结婚了？我们已经认识十几年了。

Advanced Comparison: Sometimes both 知道 and 认识 are used the same sentence.

Example sentences (both 知道 and 认识 in the same sentence): 我们已经认识十几年了，可是他的很多事情我都知道。小李，你不知道我有女朋友吗，她是咱们去年在南京旅游的时候认识的那个大学生。