Prepositions in Relative Clauses (Formal)

In casual English, we often end sentences with prepositions. This is called a "dangling preposition." It is perfectly fine for daily chats. However, formal writing prefers a different structure. We take the preposition from the end. We place it before the relative pronoun. This relative pronoun must be whom for people. It must be which for things. You cannot use who or that here. This change shifts the tone immediately. It moves from "coffee with a friend" to "meeting with the CEO." Think of it as rearranging furniture. The room stays the same. The layout just looks more organized. Yes, even native speakers find this a bit fancy. But using it correctly makes you stand out. It shows you have a high level of control.

1. 1Creating these clauses follows a very logical path. Follow these four steps to get it right every time.
2. 2Identify the relative clause in your sentence.
3. 3Find the preposition at the end of that clause.
4. 4Move that preposition to the front of the clause.
5. 5Choose the correct formal pronoun: whom or which.
6. 6For example, start with: "The project I worked on."
7. 7Step 1: The relative clause is "I worked on."
8. 8Step 2: The preposition is on.
9. 9Step 3: Move on to the front.
10. 10Step 4: Use which because a project is a thing.
11. 11Result: "The project on which I worked."
12. 12It is like a puzzle. You just need to move one piece. Once you see the pattern, you cannot unsee it. It becomes a fun mental game.

Context is everything in language. You wouldn't wear a ballgown to the gym. Similarly, don't use this grammar at a party. Use it when the stakes are high. It is perfect for academic essays. Use it in legal documents or contracts. It is great for professional emails to a boss. If you are applying for a visa, use it. If you are writing a thesis, use it. It signals that you are serious. It shows respect for the reader. In a job interview, it sounds very impressive. "The team with whom I worked was great." This sounds much better than "The team I worked with." It gives your speech a rhythmic, polished quality. Use it sparingly, though. You don't want to sound like a 19th-century poet. Balance is key to modern English.

Avoid this structure in casual conversations. If you are ordering pizza, keep it simple. Don't say, "The pizza for which I paid is late." The delivery driver might look at you strangely. Avoid it in text messages to friends. It can make you seem cold or distant. It can also feel a bit "stiff" in modern fiction. Most native speakers use the informal version 90% of the time. If you use it too much, you might sound like a robot. Or a very confused time traveler. Use the informal version for hobbies and family. Use the informal version for social media posts. Grammar is a tool, not a cage. Choose the right tool for the right job.

One big mistake is using who after a preposition. You must never say "The person to who I spoke." That is a major grammar crime. Always use whom after a preposition. Another mistake is using that. You cannot say "The car in that I sat." It must be "The car in which I sat." Some people also forget to remove the preposition from the end. They say, "The house in which I live in." This is redundant. It is like wearing two hats at once. Just use the preposition once at the front. Finally, don't force it. If the sentence becomes too long, it might break. If it feels like a tongue-twister, simplify it. Even formal English should be clear.

Let’s compare the formal style with the informal style.

Informal: "The man I was looking for."

Formal: "The man for whom I was looking."

Informal: "The city I moved to."

Formal: "The city to which I moved."

Notice the pronoun that. In informal English, we use that often. "The book that I read." But in the formal version, that disappears. We only use which or whom. Also, notice the "zero relative pronoun." In informal English, we often drop the pronoun. "The girl I talked to." In formal English, you must keep the pronoun. "The girl to whom I talked." You cannot drop it. It acts as an anchor for the preposition. This makes the formal version longer. It also makes it much more precise.