In everyday English conversations, especially informal ones, it’s quite common to hear people say ‘by who’ instead of the more grammatically traditional ‘by whom.’ While the difference between these two may seem minor, it can actually influence how polished and professional your speech or writing sounds. For learners of English or those aiming to improve their grammar, understanding the distinction between by who and by whom is essential. The confusion arises from their similarity, but each plays a specific role within sentence structure. This topic explains the difference in detail and offers practical advice to use each phrase correctly.
Understanding the Basic Grammar Rules
Subject vs. Object Pronouns
To understand the difference between ‘by who’ and ‘by whom,’ we must revisit the difference between subject and object pronouns. ‘Who’ functions as a subject pronoun, meaning it performs the action in a sentence. ‘Whom,’ on the other hand, is an object pronoun and receives the action.
- Who= Subject pronoun (e.g., He, She)
- Whom= Object pronoun (e.g., Him, Her)
When you use a preposition like ‘by,’ you are generally introducing an object, not a subject. Therefore, ‘by whom’ is the grammatically correct construction in most formal situations.
Examples in Real Sentences
Using ‘By Whom’
Let’s take a look at some examples where ‘by whom’ is used correctly:
- The letter was writtenby whom?
- By whomwas the book authored?
- This sculpture was carvedby whomin the 18th century?
In each of these examples, the phrase by whom follows a passive voice structure. The person doing the action is introduced after the verb, and ‘whom’ acts as the object of the preposition ‘by.’
Using ‘By Who’ Informally
Although by who is grammatically incorrect in formal English, it is still commonly used in informal speech. Here are some examples you may hear in casual conversation:
- Who was this made by? â More informally: This was madeby who?
- This report was preparedby whoexactly?
Note that while these constructions are common in informal language, they would typically be flagged in academic writing, journalism, or business correspondence.
Why the Confusion Happens
Similarity in Sound and Use
The confusion between ‘by who’ and ‘by whom’ is largely due to the fact that ‘who’ has become a default word for asking questions. As modern English evolves, the distinction between subject and object pronouns in questions has become less strictly enforced in casual contexts.
Lack of Exposure to Formal Grammar
Many native speakers are simply not taught or do not remember the grammatical rules that dictate when to use ‘whom.’ As a result, who often replaces whom in all contexts, including after prepositions such as by.
Simple Trick to Know Which to Use
Substitute With He or Him
A helpful rule to determine whether to use who or whom is to substitute the phrase with he or him.
- If he makes sense, usewho.
- If him makes sense, usewhom.
Let’s apply this trick:
Original: By ______ was the book written?
Test: Was the book written byheorhim? â ‘Him’ makes sense, so the correct form is ‘whom.’
Correct: Bywhomwas the book written?
When Formality Matters
Academic and Professional Writing
In academic, legal, or professional settings, precision in language is important. Using by whom instead of by who shows your grasp of formal grammar and can create a more refined impression. It’s especially critical in resumes, cover letters, reports, and scholarly topics.
Everyday Conversations
While by whom is correct, using by who in friendly discussions or spoken English is unlikely to raise eyebrows. Many people will not even notice the error because the informal style allows for more grammatical flexibility.
Grammar Evolution and Modern Usage
Changing Language Norms
English is a living language that adapts to how people use it. Over time, strict grammar rules may relax. Some grammarians argue that whom is becoming obsolete, as most people use who in both formal and informal contexts. Despite this trend, using ‘by whom’ correctly still demonstrates a solid understanding of traditional grammar.
Stylistic Choices
Writers and speakers today often choose between sounding natural or sounding grammatically correct. In storytelling, marketing, or entertainment, sounding too formal can sometimes create distance. In these cases, by who might be preferred for a more relatable tone, even if it bends grammatical rules.
Teaching Tips for Learners
Practice with Passive Voice
Because by whom typically appears in passive constructions, practice sentences using the passive voice to build comfort:
- The painting was admired by whom?
- By whom was the meal prepared?
- That speech was written by whom?
Use Fill-in-the-Blank Exercises
Provide sentence structures where learners must choose between who and whom. This reinforces understanding of subjects vs. objects.
‘By Who’ vs. ‘By Whom’
While by whom is grammatically correct and suitable for formal contexts, by who has become an acceptable variation in casual language. Knowing when to use each depends on the setting and your communication goals. If you’re aiming for formality, clarity, and correctness, ‘by whom’ is the better choice. However, if you’re having a relaxed conversation or writing informally, ‘by who’ may be acceptable and even preferred for its simplicity.
Ultimately, mastering the use of by whom over by who adds precision to your language and helps you stand out as someone who pays attention to detail. It’s a small but meaningful distinction that can enhance your overall fluency in English.