Ellipses serve as indicators of a trailing off, a 'to be continued', a sudden pause in thought or speech, an allusion to something more, a passing of time…we all understand this, but ellipses become a little more problematic when we consider their potential relationships with spaces and full-stops.
Consider the role of the ellipses in the two following sentences:
I didn't go to the zoo in the end…and that's OK because I can go tomorrow. I wasn't able to find much to do this summer… It's not fair; shelly found lots of things, though. It's not fair.
A slight nuance, but the spacing in the second sentence shows that we have moved on slightly from the initial topic. In the first sentence, the absence of spacing indicates that what follows is a direct follow-on, that the speaker paused briefly and continued speaking; however, the ellipsis in the second sentence could, indeed, be replaced by a full-stop, and ‘It's not fair…’ could be the beginning of a new sentence altogether.
This is because the ellipsis here serves to replicate real-life speech. Whilst in the first sentence, without the spacing, the ellipsis implies that the speaker paused or trailed off before regaining momentum and continuing their sentence, the ellipsis in the second sentence implies that the speaker had intended to stop completely but then thought of something else and added this on soon after as an afterthought.
NB the capitalised first letter after the ellipsis with spacing, too. This further emphasises a change in topic or the starting of a new and altogether-different sentence.
Another example of spacing with an ellipsis:
I usually walk my dog on Thursdays… Is that when you go swimming?
Here, the ellipsis is used again to acknowledge that the speaker intended to stop but thought of something else and added this on. It also implies a certain passing of time; without this spacing, one would assume that the speaker trailed off only to ’interrupt themselves’, so to speak, with a new idea. Consider the sentence below, for example, of the use of ellipsis without spacing:
I usually walk my dog on…oh! Is that when you go swimming?!
Ellipses and Full-stops
Though this is often debated amongst the grammarians, the ellipsis can also be used in some cases with a full-stop. This is a stylistic decision and is made when the ellipsis indicates a change in mood, tone or volume and comes at the end of a paragraph or piece of writing.
Consider these four endings:
Endings without full-stops: To be continued… Just then, the thug hits me over the head and… Endings with full-stops: And such was the fate of the land, as the prophecy had foretold…. And it is here that our tale concludes….
The implication of this very first ending is that there is more of the story to come, it has not yet ended, and so the absence of a full-stops emphasises the unendingness of the narrative. In the second ending, if we imagine it to be the very last sentence of a book written in first person and in the present tense, the ellipsis implies that the speaker intends to continue speaking but loses consciousness and so is cut short. The sentence itself has not ended, and so a full-stop is not necessary here.
With the third ending, however, we see that the sentence has certainly finished, that’s all that the speaker intended to say, and so the full-stop serves to indicate the end of a complete sentence whilst the ellipsis serves not as a finalising mark of punctuation but as an expression of tone –– in this case, an eerie one. The same can be said for the fourth and final example, where the sentence has been complete and so requires a full-stop, but the ellipsis adds that extra bit of encapsulating intrigue, drama and suspense.
So, where sentences are, syntactically speaking, finished and complete, an ellipsis serves as an indicator of mood and tone, whereas the full-stop that follows is the final punctuation which marks the very end of the writing.