The Myth

It is often thought as grammatically correct to not place prepositions at the end of sentences. For example, let’s look at this sentence, which is supposedly incorrectly:

-Look at this snail that I just stepped on.

And it should be rewritten like so:

-Look at this snail on what I just stepped.

Of course, this is silly in conversational English. Actually, the “don’t place prepositions are the end of sentences” rule does exist…but in Latin. And from there, somehow it has leaked into English as a myth. In short, prepositions can be placed anywhere if it is needed:

-Whom did you throw the pencil at? (correct, “at whom” is needed)
-So that’s where my pencil is at! (incorrect, “at” is not needed)
-So that’s where my pencil is! (correct)

Even though it is often easy to remove the preposition to check if the sentence still makes sense, sometimes it’s not so easy when dealing with inquisitorial adverbs: when and where. So see why, just read on below.

Adverb vs. Pronoun

It is often that we hear the “Five W’s” being listed (Who? What? When? Where? Why?). But what we don’t intuitively realize is that those words belong two separate parts of speech when used before a verb in the form of a question:

-Pronouns: who, what
-Adverbs: when, where, why

Is there a difference? Why yes! Prepositions connects nouns and pronouns. Therefore, putting a preposition at the end of a question starting with “when,” “where,” and “why” will most likely be grammatical incorrect. But why are “who” and “what” pronouns but the others adverbs? Well, “who” replaces a noun, such as “John,” and “what” also replaces a noun, such as “pencil.” In contrast, “when,” “where,” and “why” actually replaces prepositional phrases because they also represent prepositional phrases:

-When: at what time
-Where: at what place, to what place
-Why: for what reason

If you prefer to use the definition of adverbs, then yes, they do modify verbs, adjectives, or other adverbs. “When” modifies the verb to come in the following question:

-When will she come?

When here obviously does not refer to a noun but instead it modifies the word to come with how soon. Similarly, “Where” modifies the verb to put in the following question:

-Where did I put my DVD?

So now you’re probably thinking, “Why does this matter?” Let’s try putting a preposition at the end of a sentence beginning with an adverb:

-When is the store open until?
-Where is Nick at?

Now, let’s replace “when” and “where” with their respective propositional phrases:

-At what time is the store open until?
-At what place is Nick at?

Then let’s reverse the sentences to their “mythically correct” orders:

-Until at what time is the store open?
-At at what place is Nick at?

And finally, it is clear what is wrong. If you need to use until, then use “what time” instead of “when.” For “where” questions, leave off the at preposition entirely, because it is not needed, not to mention grammatically incorrect. So the correct questions should be:

-Until what time is the store open?
-What time is the store open until?

-What place is Nick at?
-Where is Nick?

Part of Speech

Even though we are going off-topic here, I have to remind everyone that the cases above only apply to the “Five W’s” when used before a verb in the form of a question. In short, “who” and “what” can be used as adverbs and “when,” “where,” and “why” can be used as pronouns.

First, we look at a situation where a pronoun can be used as an adverb. “What” is used as an adverb when it modifies the verb to be, specifically It is such and this/that is.

-What a wonderful movie!
-It was such a wonderful movie!

-What a pity.
-That is pitiful.

Second, we look at a situation where an adverb can be used as a pronoun. “Where” is used as a pronoun when it replaces “a place” and not “at a place.” This the following case, “where” is too ambiguous to specify “to what place” or “from what place,” so the prepositions “to” or “from” needs to be present, and where thus loses its implied preposition to become a pronoun:

-He drove 25 miles from where he started.
-He drove 25 miles from his house where he started.

“Where is” first and foremost implies “at what place is” or “to what place is,” so only use where as a pronoun if the implied preposition is something else.

-Where are you at? (incorrect, at is implied, where is adverb)
-Where are you going to? (incorrect, to is implied, where is adverb)
-Where are you from? (correct, from is not implied, where is pronoun)

Final Words

In conclusion, English is a language of exceptions and myths, so be careful of all the tiny nuissances of the common pronouns/adverbs. It is grammatically correct to place prepositions anywhere in the sentence, as long as it connects with a noun or pronoun, not an adverb. As Winston Churchill reportedly to have mockingly said, “Ending a sentence with a preposition is something up with which I will not put.” So the bottom line is that you don’t have to.*

*Note that I didn’t end the sentence with a preposition! The verb I use was “to have to,” not “to have,” both of which have different meanings! This yet another nuissance of English.