Languages that use inflection to convey meaning often do not have strict rules for word order in a sentence. For example in Latin both Dominus servos vituperabat and Servos vituperabat dominus mean "the master was cursing the slaves", because servos "slaves" is in the accusative case showing that they are the grammatical object of the sentence and dominus "master" is in the nominative case showing that he is the subject. Other languages, however, use little or no inflectional processes and instead use the sequence of words in relation to each other to describe meaning. For example in English the two sentences "the slaves were cursing the master" and "the master was cursing the slaves" mean different things because the role of grammatical subject is encoded by the noun being in front of the verb and the role of object is encoded by the noun appearing after the verb.

Syntax then, has to do with the order of words in sentences, and specifically how complex sentences are structured by grouping words together in units, called phrases, that can occupy different places in a larger syntactic structure. Below is a graphic representation of the syntactic analysis of the sentence "the cat sat on the mat". The sentence is analysed as being constituted by a noun phrase, a verb and a prepositional phrase; the prepositional phrase is further divided into a preposition and a noun phrase; and the noun phrases consist of an article and a noun.