One of the main functions of the full stop is to separate sentences. For example:
The Christmas break was very relaxing. I feel ready to tackle the term ahead.
Here, the full stops mark the separation between what David Crystal calls ‘units of sense’ – they help to aid clarity. The tricky, but undoubtedly rewarding challenge for us all, whether we’re emailing or composing a future bestseller, is in deciding on how best to divide these ‘units of sense’. Anyway, enough of that for now. Here’s an example from A Streetcar Named Desire, a play written by Tennessee Williams, where full stops are used in Blanche DuBois’s early dialogue to make her responses to a bit of polite chit-chat unmistakably clear:
EUNICE: I think she said you taught school.
EUNICE: And you’re from Mississippi, huh?
The extract above is taken from the first scene of the play. Blanche DuBois, described by Williams as a ‘delicate beauty’, has just arrived in New Orleans to pay a friendly visit to her younger sister. However, from the moment Blanche appears on stage, it’s clear that she is uncomfortable in her new, bohemian surroundings. Fortunately, she soon meets a young lady named Eunice, who directs her to the right apartment. In the conversation that follows, Blanche responds to Eunice’s attempts to start a conversation with neutral, grammatically autonomous, statements. She confirms that she was a teacher, and that she’s from Mississippi, but doesn’t offer any additional details about her life. Here, Blanche, at least superficially, is in charge: her dialogue is clear and controlled.
However, by the second scene of the play, Blanche’s earlier brusque command of language has vanished. In the example below, she responds to a question from her brother-in-law, Stanley Kowalski, who she believes is ‘a little bit on the primitive side’:
STANLEY: I don’t want no ifs, ands, or buts! What’s all the rest of them papers?
BLANCHE: There are thousands of papers, stretching back over hundreds of years, affecting Belle Reve as, piece by piece, our improvident grandfathers and father and uncles and brothers exchanged the land for their epic fornications – to put it plainly!
Here, Stanley (wrongly) believes that Blanche has inherited a grand and valuable country estate (Belle Reve). He is unaware at this stage that, actually, she is in a most desperate financial predicament. Blanche quickly loses control under his fierce questioning, and this is reflected by the syntactical complexity of her dialogue. In a single sentence – or ‘unit of sense’ – she attempts to provide Stanley with a condensed history of her ancestral misfortunes and, in doing so, loses the clarity and control that she exhibited earlier in the play during her frosty conversation with Eunice. Poor Blanche!
And that’s the end of another literacy shorts bulletin… However, if you would like to test your knowledge of full stops (and who wouldn’t?), this is a decent resource:
TL;DR: The main job of a full stop is to show that a sentence – ‘a unit of sense’ – has come to an end.