How does the Chinese room argument distinguish syntax from semantics?

The Chinese room argument was developed by John Searle to challenge the view of strong artificial intelligence, which posits that human intelligence is functionally equivalent to a computer program manipulating symbols.12

Searle distinguishes between syntax and semantics by highlighting the limitations of rule-based processing. In his thought experiment, a person who does not understand Chinese uses a manual to transform input symbols into output symbols based solely on their formal, or syntactic, properties—their shape and arrangement. Although the person can produce responses that appear correct to a native speaker, they possess no grasp of the semantic properties, or the actual meanings, of those symbols.312

Searle argues that because the person (or a computer) can successfully perform these syntactic operations without any understanding of the content, mere symbol manipulation cannot be equated with genuine human thought or intelligence. Consequently, he asserts that functionalist theories, such as those once held by Hilary Putnam, are deficient because they define thinking as the manipulation of symbols according to syntactic rules while failing to account for the essential semantic properties of mental states.23