Is ending a sentence with a preposition allowed?
To begin the answer to this question, we need to travel to the year 1672 and a quarrel that the English playwright and poet John Dryden picked with (then deceased) fellow writer Ben Jonson. In Dryden’s book Defence of the Epilogue, he complained that, in his poem Catiline, Jonson had left ‘the Preposition in the end of the sentence; a common fault with him’.
However, it seems Dryden had completely invented this problem with the dangling preposition, even though there were plenty of examples of them in his own earlier works and despite the fact, it was a common occurrence in standard English.
The philosophy behind this attempt to change the rules of English grammar was to make English behave grammatically more like Latin; the same went for the visceral horror inspired by split infinitives (which are also normal in English). Other writers from the period and later have felt that English could be improved by following this Latinate methodology, and the stranded preposition has entered into the mythic folklore of English grammar. However, it is only a myth – don’t have nightmares.
Because of this misunderstanding, even though the writer knows they are correct, they often prefer to move the preposition in order to avoid controversy or unfounded accusations of illiteracy.
When ending a sentence with a preposition is fine
There are a few situations in which a stranded preposition is preferable to the tortured syntax resulting from trying to manoeuvre one in front of its complement. Otherwise,
Relative clauses, for example, such as she’s exactly the kind of powerful woman I’m attracted to, sound far more natural than the Dryden-favoured alternative. She’s exactly the kind of woman to whom I’m attracted does not lend confidence that the romance will smoulder through the ages.
Open questions beginning with who, which, what, where and other wh– words also work perfectly well after shunting the preposition to the other end. What did you mention split infinitives for? is a good example, allowing the exasperation of the speaker or writer to be expressed more fully than starting with why.
What a fine mess you’ve left me in! exclaims, whereas In what fine mess have you left me! confuses. So, it’s fine to leave the preposition at the end.
Sentences in the passive voice also tend to dangle their prepositions: this bed is barely slept in.
Infinitive clauses (featuring the infinitive form of a verb, like to deal) will also normally leave the preposition stranded: this is too much to deal with, for example.
Set phrases (like to speak of, or to live with) also allow prepositions to dangle, as in Chris was a difficult character to live with, because the phrase would sound strange if it was changed.
Think of it this way. If these examples would sound strange with the preposition moved, then how can there be a rule banning the stranded preposition? Strangest thing I ever heard of!