In school, you were taught that the rules of grammar should never be violated: use apostrophes to connote possession, join two ideas using a semicolon, and never end a sentence with a preposition.

Unlike apostrophe usage, however, sticking closely to the preposition rule can sometimes make sentences clunky or confusing. The truth is that including a preposition at the end of a sentence is not always bad grammar. In fact, the anti-preposition rule is largely a myth.

Introduction to Prepositions and Prepositional Phrases

A preposition is a word that connects a verb, noun, or adjective with a noun or pronoun, showing the relationship between the two or another element in that same clause or sentence. In the sentence, “The cat sat between the two trees,” the word “between” is a preposition because it establishes how one noun (the cat) is situated among the other nouns (trees). Prepositions often deal with time and location, such as “behind,” “after,” or “over.”

It's useful to have a go-to rule for determining whether a given word is a preposition. One option is to place the word in this sentence: “The mouse goes ______ the box.” If the word makes sense in the sentence, then it is a preposition. However, if a word does not fit, it may still be a preposition — for instance, prepositions like “according to” or “notwithstanding."

Prepositional phrases are groupings of at least two words, consisting of, at minimum, the preposition and the object of the preposition, aka, the noun it precedes. For example, “near the ocean,” “without gluten,” and “before bed” are all prepositional phrases.

Origins of the Preposition Rule

In the 17th and 18th centuries, Latin grammar rules were applied to the English language. In Latin, the word “preposition” translates roughly to the words for “before” and “to place.” However, in the years that followed, many have argued that trying to make English conform to Latin standards is not always practical, and that the preposition rule should not be followed if it damages the integrity of the sentence. One famous example is Winston Churchill's declaration after someone criticized him for ending a sentence with a preposition: “This is the sort of English up with which I will not put!”

Rules for Ending a Sentence With a Preposition

If, in the process of avoiding ending a sentence with a preposition, the sentence begins to sound awkward, overly formal, or confusing, then it's acceptable to ignore the preposition rule. However, it is still best to try to conform to this rule if it does not alter clarity, particularly in professional and academic writing. For example, “What building is he in?” could easily be changed to: “He is in which building?”

Here are some situations in which ending a sentence with a preposition is acceptable:

When beginning a sentence with who, what, where: “What area of research is she interested in?”

Infinitive structures, or when the verb is left in its basic form (ie, “to swim,” “to contemplate”): “She had nothing to think about,” “He had no music to listen to.”

Relative clauses, or a clause starting with the pronoun who, that, which, whose, where, or when: “She was excited about the responsibility that she was taking on.”

Passive structures, or when the subject of a sentence is being acted upon by the verb, rather than doing the verb’s action: “She liked being sick because then she was taken care of.”

Phrasal verbs, or verbs that consist of multiple words, including a preposition: “She needs to log on,” “When I was having a bad day, my sister told me to cheer up.”

Because the preposition rule has long been ingrained in language education, potential employers or other business colleagues may believe this rule needs to be upheld. In professional scenarios, it's best to play it safe and avoid prepositions at the ends of sentences. However, if you believe that abandoning this rule is best for your writing, you're in good company: successful writers and orators have been doing it for centuries.