Syntax refers to the rules that govern how words combine to form phrases, clauses, and sentences in a language. It involves word order and concord. Word order concerns the arrangement of words in a sentence, such as subject-predicate order. Concord involves agreement between parts of a sentence in properties like number, gender, and tense. The main parts of syntax are word order and concord. Word order establishes patterns like subject-predicate, while concord requires agreement between nouns and verbs in properties such as person, number, and gender.