Psychology 1000-002 assignment #4: what is the difference between syntax and semantics and to what kinds of. Give an example of how changing the syntax of a phrase or sentence can change its semantics. Syntax is a surface structure that refers to formal rules governing the construction of valid statements in a language. Semantics on the other hand refers to the set of rules, which give the meaning of a statement. Syntax applies to surface structure, which are the words that are actually being spoken or used in a certain way. Semantics applies to deep structure, which is the underlying meaning of the sentence being used. The change in the syntax of a phrase can change its semantics. An example of this is using the sentence the police must stop drinking after midnight , by changing the syntax of this phrase into the drinking of people after midnight must be stopped by the police .