Comparing "lijie" and "liaojie"

理解 vs. 了解

Similarities:

Parts of Speech: both are verbs.

Meaning: Both mean “understand” or “comprehend” a person or the way something is.

Collocations: These patterns work with both 理解 and 了解：很～你, 不～你, 不太～, 互相～,

   Example sentences ( 理解 AND 了解 both can be used):

一 二 三 四

Differences:

Formal/Informal: 理解 is used much more often in formal settings and written Chinese, whereas 了解 is used both in formal/informal settings and written/spoken Chinese.

Meaning: 理解 means after much thought and deliberation “to grasp an understanding of ” a principle, a reason, material, a person’s deep inner thoughts or feelings.

Collocations: These patterns work only with 理解：不能～, ～不了, ～力, ～错了, 表示～

Example sentences (only 理解 can be used): 一 二 三 四

Meaning: 了解 means “to know about”, “to know of”, “to think about” a person or concept.

Example sentences (only 了解 can be used): 一 二 三 四

Meaning: 了解 means “to get to know” or “to find out about” “to become aware of how something will work out“ (think “ahh… got you!”) of a condition or a situation.

Collocations: These patterns work only with 了解：～情况, ～一下, 了解了解

Example sentences (only 了解 can be used): 一 二 三 四