English grammar - Roger Berry 2012
A12.3 Basic differences: intonation and punctuation
A12 Grammar in speech and writing
Section A. Introduction
In this book, grammar is treated as being neutral to speech or writing; rules have been specified without mention to either, for example for the definition of the sentence in A9, where the traditional writing-based definition was rejected. Admittedly, the role of writing (e.g. in the shape of spelling and punctuation) is occasionally given some attention; see, for example, the use of commas to mark off comment adverbs in B4, but this is only because it is easier to illustrate.
However, there are a number of areas where we cannot ignore the differing effects of the mode on grammar, where there are basic grammatical features in one mode that cannot be mapped onto features in the other mode. For instance, there may be different morphological arrangements in speech and writing; the regular plural morpheme in English, which has two written but three spoken forms (as we noted in A2), would be an example.
The main difference between speech and writing is the use of intonation (and other suprasegmental features such as stress) in the former and punctuation in the latter. The two sometimes correspond; for example, a question mark in writing with a yes/no question can be equated to a rising intonation in speech:
And a word space may correspond to a double stress pattern to distinguish a premodifier + noun from a compound noun (e.g. black bird vs blackbird). However, most punctuation has no obvious equivalent in speech. Commas may indicate pauses, but equally they may have a purely grammatical rationale.
There are some features of grammar in writing that are not reflected in speech, for example the difference between the plural, genitive, and genitive plural of nouns (dogs, dog’s, dogs’), though this does not seem to affect intelligibility. In general, however, intonation is a much more sophisticated tool for marking grammatical distinctions than writing. Different types of tag questions, for example, are distinguished by intonation in speech, as described in B9, while their written form is the same.
A full account of the connection between grammar and intonation (and indeed between punctuation and grammar) is not feasible here. Some references are mentioned in the further reading.