If you want to write well, learn to love the full stop. See it as the goal towards which the words in your sentence adamantly move.
So advises Joe Moran, Professor of English at Liverpool John Moores University, in an article that sings the praises of that dot at the end of a sentence, a dot that is increasingly missing in social media. Studies have been done into the effect of the fullstop; these suggest that people tend to read a text message that ends with a full stop as curt or passive-aggressive. Maybe, but maybe also people just don’t text using complete sentences.
In formal writing, sentences are necessary. Here’s Moran again:
A good sentence moves smoothly and cleanly towards a stop. The best way to ensure this happens is to put the important stuff at the end. A sentence ordered like this feels more deliberate and more memorable just as, when you stop speaking, what sticks in your listener’s mind is the last thing you said. A sentence’s strongest stress falls on its last stressed syllable, just before the full stop.
Until Aristophanes of Byzantium invented the dot or periodos to signal a complete thought, sentences just went on and on and on. Here too is the origin of the American word for ‘full stop’, the ‘period’. According to Anglophile Fraser McAlpine during the 18th and 19th centuries a distinction was made between the period – the dot itself, also used then (but see below) to end abbreviations and initials – and the full stop, which was only ever used to end sentences. In the 20th century, for reasons that are not entirely apparent, the generic term for that dot shifted within British English and it became more commonly referred to as a full stop even when used for other purposes.
I’d like now to turn to one of the most surprising discussions that occurs in my training sessions: the debate about the number of spaces used after the full stop. Is it one or two? In the age of the computer and modern fonts, the answer is one. Before that, because typefaces and printing were less clear, the practice was to have a larger space between sentences. When typewriters were invented in the 1860s, typists achieved this by using two spaces. That practice was drummed into all who learned touch typing and, remarkably, seems to have carried over to many who have learned to type on a computer keyboard.
This is a matter of style not grammar, so where else, in Australia at least, to get the answer than the Style Manual, which on page 97 says:
[The full stop] should be followed by one space only.
Later on the same page and on pp 152-153, the manual gives a list of the places where not to use the full stop (note still two words). Here too the modern trend towards minimal punctuation means entrenched habits must be abandoned. For shortened words that are contractions, that is words consisting of the first and last letters of a word, no full stops are necessary.
For example: Mr Mrs Rd Qld dept
If the shortened word is an abbreviation, consisting of the first letter of the word, usually some other letters but not the last letter, the manual says to use a full stop.
For example: para. Mon. Vic. cont.
The latest edition of the manual was, however, written in 2002 and things have moved on, with these full stops now being dropped too. So, when in doubt, remember that the most important thing is to use punctuation to help your reader get your message. Full stop (period).