The title of this post bothers me. It just feels awkward.
So, I can just rewrite it, can’t I?
There! That’s an example of a contraction that would never be ‘un-contracted’.
We’d never say:
…I can just rewrite it, cannot I?
Let us go to the park. (let’s)
You forgot to do your homework, did not you? (didn’t)
Could not you wash the car later? (couldn’t)
These are examples of expressions that are no longer used in their un-contracted forms. Speaking them in full feels a bit ‘ye olde’. (By the way, ‘ye’ was never a word. The y is a typesetter’s substitution for the old English character thorn—Þ—which was always pronounced as a voiced th.)
English is full of these relics, throwbacks to old words or expressions, that often only remain in a single contemporary term or expression. Like ‘teller’ in ‘bank teller’. Tell is an old word meaning ‘to count’, and we don’t see it anywhere else. Another example is in the expression ‘short shrift’. What is a ‘shrift’, you ask? A shrift is (in the Catholic church) the act of confessing your sins and having them forgiven. This is something that people condemned to death were expected to do, and if they would be so kind as to get it over with quickly, they could be knocked off and the rest of us could get on with our day, or dinner, as Shakespeare would have it in Richard III (1594)—the first recorded use of the expression.
Dispatch, my lord; the duke would be at dinner.
Make a short shrift; he longs to see your head.