How does John Searle distinguish syntax from semantics in the Chinese room argument?

In the Chinese room argument, John Searle distinguishes between syntax and semantics to challenge the claims of strong artificial intelligence.

Searle argues that computer programs function solely by manipulating symbols based on their formal or syntactic properties—the rules governing the arrangement and transformation of symbols. However, he asserts that this process lacks semantic properties, which involve the actual meanings of those symbols.1

In his thought experiment, a person inside a room uses a manual to transform input strings of Chinese characters into output strings. While the person can successfully simulate an understanding of Chinese by following syntactic rules, they possess no actual comprehension of the language. Searle concludes that because the system operates entirely through symbol manipulation without grasping the underlying meaning, it does not exhibit genuine intelligence or thought. Thus, he maintains that syntax is insufficient for semantics, and computers merely simulate intelligence rather than possessing it.21