After the possessive case, contraction is the busiest workplace for the humble apostrophe.
This is the original usage of the apostrophe in the English language, going back to the 16th century, and perhaps where issues around its use are simplest before all the tricky sibilant word endings became involved.
In this case, the apostrophe shows that some letters are missing from the word.
Examples of apostrophes and contraction
I will go to the doctor tomorrow becomes I’ll go to the doctor tomorrow.
However, have can be used in two different ways (the present perfect and the present tense), which is reflected in the punctuation.
The present perfect will happily drop a couple of letters and become I’ve (for example, I’ve just bought a cake), but the present tense must remain intact (for example, I have a terrible allergy to cake and not I’ve a terrible allergy).
This does not reflect actual speech, which often abbreviates I have to I’ve, but rather the written standards.
Several words came to lose their apostrophes in English over the course of the last century as the words themselves become more familiar.
Why not take a glimpse into the history of the language to see what has changed? A violoncello went from ‘cello to cello, while we no longer use ‘phones to call into work to tell them we have ‘flu.
Some words have managed to make it all the way from the distant past without losing their apostrophes at all: words like fo’c’s’le, rock ‘n’ roll, o’er and ne’er-do-well.
It is difficult to know how long it might be before those few remaining punctuation marks are also airbrushed out of the dictionary.
Its and it’s
This is another chestnut that occasionally lodges in the gullets of right-thinking grammarians: the apparent inability of many authors to recognise that it’s is generally short for it is.
Without the apostrophe, however, the word its is the possessive version of it, as illustrated below.
Example of contraction
The dog loves its bone because it’s delicious (The bone belongs to the dog, but the bone is also delicious)