Syntax is the study of the rules that control how language is structured first into clauses and then sentences. It can be compared with semantics, which is the study of how meaning is created by words.
Variations in syntax in different forms of English are unusual, but do exist. Indian English, for example, has some different syntactic rules to other Englishes.
In the classroom
Clause structure is an area of syntax which many teachers spend a lot of time looking at with learners, especially when practising writing skills.