Prepositions are words that come before a noun and govern the relationship – often related to time (‘temporal’) or place (‘locative’) – between that noun and another element in the sentence. For example in ‘John is in bed’, in shows you the spatial relationship between John and his bed – ‘John is under his bed’ shows a very different spatial relationship. If you say ‘I’ll meet you at ten’ and I turn up some time after ten, you’ll not be happy about it: ‘What manner of temporal relationship with ten did you think I was expressing?’ you might ask me angrily. The preposition naturally comes before the noun: no native English speaker in their right mind would say ‘I’ll meet you ten at’ or ‘John is his bed under’. This is why it’s called a preposition – the prefix pre- means ‘before’. In languages where it naturally comes after the noun, like Korean (열시에 – ‘ten o’ clock at’), we would call these words ‘postpositions’.
Because of its name, someone somewhere back in the mists of time declared that ‘No preposition should ever under any circumstances end a sentence’, and people have been arguing about it ever since. What about questions, for example?Word order has to change in a lot of questions, so shouldn’t we change the position of the preposition too? We could say ‘Under what is John?’ but it sounds rather forced – it would be much better just to say ‘What is John under?’
‘Oh yeah,’ says someone somewhere back in the mists of time, ‘I see what you mean. I’ll grant you that then: prepositions are alright at the end of questions, but that’s all.’
That’s not all though. There are phrasal verbs to contend with too. Phrasal verbs are verbs that consist of more than one word, usually a verb and one or two particles, usually prepositions: ‘We put our friend up for a few days and we ran out of milk. Sometimes when we’re using a phrasal verb, the preposition will naturally come at the end of the sentence, as in ‘We put her up’ and we’re hard pressed to think of where else we could put it if we want to follow that silly old ‘rule’. Winston Churchill heard this ‘rule’ about prepositions and came up with one of his famous rejoinders:
That is a rule up with which I will not put.
The point that this demonstrates is that if we always insist on the ‘rule’ about prepositions we can end up with ridiculous sentences. If following rules leads to silly sentences, better to disregard the rule.
Think of some other sentences that would end up looking quite ridiculous if you didn’t put the preposition at the end.