Because subject-object relationships are expressed in Classical Slith by case endings, word order is relatively free. Ksēvon vīdam means I see the man, but so does Vīdam ksēvon; the order doesn't impact the grammatical meaning of the sentence. In such a situation, word order conveys emphasis, not meaning. For instance, Ksēvon fālaktet khthōrom means I killed the man with a spear, and Khthōrom fālaktet ksēvon means the same thing, but the latter places more emphasis on the fact that the speaker killed the man, instead of just injuring him.
Such subtlety is hard to render in translation.
The most normal, unemphatic word order in Classical Slith is subject-indirect object-direct object-verb, with modifiers as near to the things that they modify as possible. However, the subject is often unexpressed, and there frequently is no indirect object. Additionally, it is not uncommon for the direct object to follow the verb (especially in informal writing, where it becomes the norm).
Thus, a standard way of saying The man spoke the speech to me is Ksēvoss mōthi hessem hessoth. It would not be unusual to say mōthi hessoth hessem casually. For emphasis that he spoke the speech to me and not someone else, hessem hessoth mōthi.
Modifiers tend to follow what they are modifying, although the tendency is very slight. The noble man is likely to be expressed Ksēvoss kālōs, although it could very easily be expressed Kālōs ksēvoss as well. The major exception is the genitive case: a possessive genitive is noticeably more likely to precede, whereas a partitive is likely to follow. For example, The man's speech is Ksēvose hess, but A flagon of ale is Kālīs fērletke.
One near-rule is that conjunctions (and relative pronouns) must almost always come at the beginning of the clause that they introduce. In Archaic Slith, some transition words were frequently post-positive, but that tendency ended at the dawn of classical prose. Thus, one would almost invariably say Ksēvoss kō hessath for The man who speaks rather than Ksēvoss hessath kō. The placement of conjunctions and relative pronouns is generally very regular.
Good classical prose frequently involves very long and very complicated sentences. One cause of this is the tendency to create different levels of subordination. For example, Bainathōn morāni ksēvon kō hessoth thōthi mō khthōrom loosely translates as While he was walking on the mountain, the man who spoke to you was the one whom I killed for you, except less strained. The participle sets up the circumstances of the event but are not emphasized strongly. The relative clause describes the cause of this action (presumably), which is that the man spoke to the addressee ("you"). Since the cause is an important sub-component of the action, it is a level above a participle. However, the main clause is reserved for the action: I killed the man. These layers of subordination can pile on top of each other, creating extremely long sentences.
Another feature of this sentence is the drawn-out structure of the main clause. The direct object appears early, in the first three words, but the grammar of the sentence is not completely resolved and the meaning finished until the very final word, the main verb. Good classical prose more often than not keeps subordinate clauses or extra descriptive words within the middle of the main clause, instead of adding them at the end or beginning, leading to the most important words appearing at the beginning and the end of the sentence (here, khthōrom). The grammar and meaning remaining unresolved until nearly the final word is a major aesthetic point.
The third notable point is the sandwiching of morāni between bainathōn and ksēvon. Since the endings of the words allow one to tell that bainathōn and ksēvon agree, they can be separated by a word or two (rarely more than that, in good prose) that should be taken closely with one or both of the words. Here, morāni indicates the location where bainathōn was happening, so it is placed near that word. This is quite common, although the more extreme form, known as hyperbaton, in which words that agree or complete each other's meanings are separated by a large distance (e.g., Kālōs khātatothōn khthōroth ksēvoss to de dēghon, that is, The noble man killed the hated dragon), is very rare in good prose. (So, too, is the placement of the de, explainable in context.)
A fourth feature of this sentence is the ambiguity of the dative. The word thōthi comes between the clause who spoke and the clause I killed, making the word do double-duty: who spoke to you and I killed for you are both intended meanings of this sentence, even though the word you only appears once. Using the same word for two purposes is a feature of good classical prose.
High classical poetry follows quite different rules from those that govern prose. While the primary difference between poetry and prose is metrical, syntax and diction are also quite different.
Classical poetry is invariably in a metrical form of some sort, and the meter is dictated by the genre of poetry: epic in dactylic hexameter, love poetry in elegiac couplets, etc. The meter is formed from patterns in heavy and light syllables (see Pronunciation, under Phonetic Laws): the dactylic hexameter, for example, follows a pattern of heavy-light-light (or heavy-heavy) repeated six times per line. Prose deliberately avoids the heavy/light patterns of the major poetic forms.
Poetry also allows greater variety in word-order. Words that are normally sentence-initial, such as conjunctive particles and relatives, can be post-positive (placed second) or moved even later, hearkening back to the Archaic tongue, in which several of the particles were commonly post-positive. Hyperbaton, while still unusual, is somewhat more common. Most significantly, there is no natural word order for subjects, verbs, and objects, in strong contrast to the tendencies listed above for conversational word order. Placement of the words throughout the sentence in poetry has much more to do with emphasis and narrative than any sense of natural order.
Verse very deliberately avoids jangly sound-devices. End-rhyme is to be avoided at all costs. Internal rhyme is nearly unavoidable, but it is de-emphasized whenever possible, and only internal slant-rhyme is unregulated. Alliteration can be used, but only sparingly. Rhythmic effects, however, are used frequently: the deployment of heavy and light syllables to make the verse quick and easy or slow and weighty is carefully controlled.