linguistic:translation, stylistic:tone, structural:reformatting
Development of grammar

Grammars evolve through usage. Historically, with the advent of written representations, formal rules about language usage tend to appear also, although such rules tend to describe writing conventions more accurately than conventions of speech. Formal grammars are codifications of usage which are developed by repeated documentation and observation over time. As rules are established and developed, the prescriptive concept of grammatical correctness can arise. This often produces a discrepancy between contemporary usage and that which has been accepted, over time, as being standard or "correct". Linguists tend to view prescriptive grammar as having little justification beyond their authors' aesthetic tastes, although style guides may give useful advice about standard language employment based on descriptions of usage in contemporary writings of the same language. Linguistic prescriptions also form part of the explanation for variation in speech, particularly variation in the speech of an individual speaker (for example, why some speakers say "I didn't do nothing", some say "I didn't do anything", and some say one or the other depending on social context).

The formal study of grammar is an important part of children's schooling from a young age through advanced learning, though the rules taught in schools are not a "grammar" in the sense that most linguists use, particularly as they are prescriptive in intent rather than descriptive.

Constructed languages (also called planned languages or conlangs) are more common in the modern-day, although still extremely uncommon compared to natural languages. Many have been designed to aid human communication (for example, naturalistic Interlingua, schematic Esperanto, and the highly logical Lojban). Each of these languages has its own grammar.

Syntax refers to the linguistic structure above the word level (for example, how sentences are formed) – though without taking into account intonation, which is the domain of phonology. Morphology, by contrast, refers to the structure at and below the word level (for example, how compound words are formed), but above the level of individual sounds, which, like intonation, are in the domain of phonology. However, no clear line can be drawn between syntax and morphology. Analytic languages use syntax to convey information that is encoded by inflection in synthetic languages. In other words, word order is not significant, and morphology is highly significant in a purely synthetic language, whereas morphology is not significant and syntax is highly significant in an analytic language. For example, Chinese and Afrikaans are highly analytic, thus meaning is very context-dependent. (Both have some inflections, and both have had more in the past; thus, they are becoming even less synthetic and more "purely" analytic over time.) Latin, which is highly synthetic, uses affixes and inflections to convey the same information that Chinese does with syntax. Because Latin words are quite (though not totally) self-contained, an intelligible Latin sentence can be made from elements that are arranged almost arbitrarily. Latin has a complex affixation and simple syntax, whereas Chinese has the opposite.