Some grammar errors are about sentence structure. These aren’t — they’re about word choice, and they’re some of the most frequent corrections in any copy edit, showing up even in manuscripts that are otherwise clean and polished. Here’s the list worth knowing cold.
Lay vs. Lie
This is the single most commonly confused pair in English, and the confusion is understandable — the past tense of lie is, unhelpfully, lay.
- Lie (no object): to recline. “I need to lie down.” Past tense: “I lay down yesterday.” Past participle: “I have lain down.”
- Lay (takes an object): to put or set something down. “Lay the book on the table.” Past tense: “I laid the book on the table.” Past participle: “I have laid the book on the table.”
The test: does the verb have an object — something being laid down? If yes, it’s a form of lay. If the subject itself is reclining, it’s a form of lie.
- Wrong: “She laid down on the couch.”
- Right: “She lay down on the couch.” (Present tense would be “She lies down.”)
Farther vs. Further
- Farther refers to physical distance. “The store is farther than I remembered.”
- Further refers to figurative or abstract extent. “We need to discuss this further.”
A useful shortcut: if you can replace it with a specific measurable distance, use farther. If the sentence is about degree, extent, or progress rather than physical space, use further.
Affect vs. Effect
- Affect is usually a verb: to influence something. “The rejection affected her confidence.”
- Effect is usually a noun: the result of something. “The rejection had a lasting effect on her confidence.”
The exception that trips people up: effect can also be a verb meaning to bring about or cause, as in “to effect change” — which is correct, not a typo for affect, and means something subtly different (actively causing change, rather than being influenced by something).
Fewer vs. Less
- Fewer is for countable things. “Fewer readers finished the book.”
- Less is for uncountable quantities. “Less interest in the sequel.”
The quick test: can you count it one by one? Fewer chapters, fewer copies, fewer reviews — all countable, all fewer. Less time, less enthusiasm, less money — all uncountable, all less.
Who vs. Whom
- Who is a subject pronoun — it performs the action. “Who wrote this?” (Who is doing the writing.)
- Whom is an object pronoun — it receives the action. “To whom should I address this?” (Whom is receiving the addressing.)
The classic test: if you can answer the implied question with he or she, use who. If the answer would be him or her, use whom. (“Who called?” → “He called,” so who is correct. “To whom did you give it?” → “I gave it to him,” so whom is correct.)
In contemporary prose and especially dialogue, whom is fading from common usage, and using who in a technically “whom” slot often reads as more natural in casual dialogue. This is a case where grammatical correctness and authentic voice can pull in different directions — worth a deliberate choice rather than an automatic one, particularly in character dialogue versus narration.
Toward vs. Towards
Both are correct; this isn’t actually an error, just a regional variation. American English generally prefers toward; British English generally prefers towards. The only real rule is consistency — pick one and use it throughout the manuscript rather than alternating.
Compliment vs. Complement
- Compliment: praise. “She complimented his prose style.”
- Complement: something that completes or pairs well with something else. “The subplot complements the main story’s themes.”
These are pronounced identically, which is exactly why they slip past writers reading their own work aloud — the ear can’t catch what the eye needs to.
Discreet vs. Discrete
- Discreet: careful, tactful, avoiding unwanted attention. “He was discreet about the affair.”
- Discrete: separate, distinct, individually identifiable. “The novel is told in three discrete timelines.”
Another pair that sounds identical and is caught only by careful reading, not by ear.
Why a List Like This Matters
None of these errors reflect on a writer’s skill with story, structure, or voice — they’re closer to typos than to craft issues, in the sense that they’re about knowing a specific rule rather than about writing ability. But they’re exactly the kind of error that pulls a reader — or an agent, or a producer’s assistant doing a first pass — out of the story for a half-second, and half-seconds like that accumulate into an impression of carelessness that has nothing to do with how good the actual book is. A clean manuscript, mechanically, buys you the reader’s full attention for everything that actually matters.
