Walter Reed Hospital

Small words and tiny marks cause the most embarrassing errors. Scan these six hotspots every time you proofread: their/there/they're; your/you're; subject-verb agreement; prepositions; word order, punctuation & spacing; hyphenation. Each section gives a short rule, a quick test, and many practical before/after fixes you can copy.

Quick check: the six things to scan every time

Proofread in this order: (1) similar-word confusions, (2) verb matches the grammatical subject, (3) prepositions pair with the verb, (4) modifiers sit next to what they change, (5) commas and spaces are correct, (6) compound adjectives use hyphens when needed.

Expand contractions: "they are" → they're; "you are" → you're.
Find the true subject before choosing a verb - not the nearest noun.
Move modifiers next to the words they modify to avoid dangling or misplaced phrases.

Core mistakes at a glance

These six error types cause most misunderstandings. Run the short tests below as a quick filter while editing.

Their / There / They're confusion - possession vs. place vs. contraction.
Your / You're - possession vs. "you are".
Subject-verb agreement - match number to the grammatical subject.
Prepositions - verbs often require specific prepositions.
Misplaced modifiers, commas, and spacing - small moves change meaning.
Hyphenation in compound adjectives - hyphenate before a noun to join words.

Their, there, and they're - fast tests + examples

Their = possessive. There = place or existential. They're = they are. Quick tests: substitute "they are" for they're; substitute "theirs" for their. If neither works, use there.

If "they are" fits, use they're.
If ownership fits and "theirs" makes sense, use their.
Otherwise use there for location or existential sentences.

Work - Wrong: Their going to review the budget tomorrow.
Work - Right: They're going to review the budget tomorrow.
Work - Wrong: Put the files over their, on my desk.
Work - Right: Put the files over there, on my desk.
School - Wrong: Their are three answers to this problem.
School - Right: There are three answers to this problem.
Casual - Wrong: I called them and they're dog barked the whole time.
Casual - Right: I called them and their dog barked the whole time.

Your versus you're - possession vs. contraction

Your = possessive. You're = you are. Test: can you expand to "you are"? If yes, use you're; if not, use your.

Use you're when "you are" works naturally.
Use your to show ownership (your idea, your phone).

Work - Wrong: Your invited to the onboarding session.
Work - Right: You're invited to the onboarding session.
School - Wrong: Is this you're pencil?
School - Right: Is this your pencil?
Casual - Wrong: Your gonna love this song!
Casual - Right: You're gonna love this song!

Make corrections faster with example-driven checks

Ready-to-use rewrites save time. Combine quick substitution tests with a grammar checker to catch mechanical errors and polish clarity in one pass.

Keep a short file of your most common corrected sentences to paste into new drafts.
When in doubt, produce a plain rewrite first, then refine punctuation and style.

Subject-verb agreement - find the grammatical subject

Match the verb to the grammatical subject (who/what performs the action). Ignore interrupting phrases (along with, as well as, including). For compound subjects joined by and use plural verbs; for or/nor match the nearer subject.

Locate the subject first, then choose singular or plural verb form.
Ignore interrupting phrases: "The CEO, along with the managers, is attending."
For "or"/"nor", let the verb agree with the nearer noun.

School - Wrong: The list of items are on the table.
School - Right: The list of items is on the table.
Work - Wrong: My friend and colleague is presenting today.
Work - Right: My friend and colleague are presenting today. (two people)
Work - Wrong: Neither the manager nor the employees was available.
Work - Right: Neither the manager nor the employees were available.
Casual - Wrong: She don't have the notes.
Casual - Right: She doesn't have the notes.

Prepositions that trip people up

Prepositions follow patterns more than logic. If a verb sounds odd with a preposition, swap to the most common pairing and check a reliable source if needed.

Common pairings: good at, depend on, interested in, participate in, responsible for.
When unsure, look up examples of "verb + preposition" and copy the confirmed form.

School - Wrong: She's good in programming.
School - Right: She's good at programming.
Work - Wrong: It depends of your schedule.
Work - Right: It depends on your schedule.
Work - Wrong: He participated on the workshop.
Work - Right: He participated in the workshop.
Casual - Wrong: I'm interested on joining the club.
Casual - Right: I'm interested in joining the club.

Try your own sentence

Test the full sentence, not just a phrase-context usually clears up prepositions and word order.

Word order, punctuation, and spacing - clarity fixes that change meaning

Keep modifiers close to the words they change. Use commas to separate clauses and items; missing or misplaced commas change meaning. Modern spacing: one space after periods; no space before commas or periods.

Place adverbs beside the words they modify to avoid ambiguity.
Use commas after introductory phrases and to isolate nonessential clauses.
Remove extra spaces before punctuation; use a single space after a period.

Wrong: I only spoke to John who agreed.
Right: I spoke only to John, who agreed.
Casual - Wrong: Lets eat grandma
Casual - Right: Let's eat, grandma.
Work - Wrong: Hello , welcome to the team .
Work - Right: Hello, welcome to the team.

Hyphenation and compound words

Hyphenate compound adjectives before a noun (well-known author) but not after (the author is well known). Hyphenation changes over time-check a current dictionary when unsure. Use hyphens to prevent temporary ambiguity.

Before a noun: high-quality product; after the noun: the product is high quality.
Hyphenate to prevent misreading: small-business owner vs. small business owner (owner of a small business).

Work - Wrong: She is a well known speaker.
Work - Right: She is a well-known speaker.
School - Wrong: A full time student should apply.
School - Right: A full-time student should apply.

Real usage: example-packed checklists for work, school, and casual writing

Practical pairs you can reuse-copy the corrected version when you're in a hurry.

Work - Wrong: Your the project lead for this phase, please prepare an update.
Work - Right: You're the project lead for this phase; please prepare an update.
Work - Wrong: The committee, along with the director, were present.
Work - Right: The committee, along with the director, was present.
Work - Wrong: Please send the report to Mark and I.
Work - Right: Please send the report to Mark and me.
School - Wrong: Their are four sections you must answer.
School - Right: There are four sections you must answer.
School - Wrong: The data suggests that the theory holds.
School - Right: The data suggest that the theory holds.
School - Wrong: A part time student has fewer resources.
School - Right: A part-time student has fewer resources.
Casual - Wrong: Your going to love this!
Casual - Right: You're going to love this!
Casual - Wrong: I could care less about that.
Casual - Right: I couldn't care less about that.
Casual - Wrong: They're dog is so cute.
Casual - Right: Their dog is so cute.

How to rewrite your sentence in five quick steps (with examples)

Five fast steps: read aloud, find the subject and verb, test common confusions, check prepositions and commas, split long sentences to simplify.

Read it aloud - hearing mistakes often reveals them.
Split complex sentences into two shorter ones for clarity.
When stuck, write a plain rewrite first; polish punctuation after.

Rewrite: Draft: "Moving forward, the team will evaluate the project's feasibility which will be challenging."
Rewrite: "Moving forward, the team will evaluate the project's feasibility. This will be challenging."
Rewrite: Draft: "Your invited to the seminar next week but your schedule may conflict."
Rewrite: "You're invited to the seminar next week, but your schedule may conflict."
Rewrite: Draft: "Because of the complexity of the case the judge, as well as the lawyers, were cautious."
Rewrite: "Because of the case's complexity, the judge and the lawyers were cautious."
Rewrite: Draft: "She don't has the files."
Rewrite: "She doesn't have the files."

Memory tricks and similar mistakes to watch for

Short cues speed up scanning. Check related errors in the same pass.

"Their" links to "theirs" (possession). "You're" has an apostrophe - expand to "you are."
"Fewer" for countables, "less" for mass nouns: fewer items, less water.
"Affect" (verb) vs. "effect" (noun). "Who" (subject) vs. "whom" (object).
Check I/me placement: "Tom and I went" vs. "Send to Tom and me."

Wrong: I could of helped you.
Right: I could have helped you.
Work - Wrong: Please contact Janet or myself.
Work - Right: Please contact Janet or me.
Usage: Effect (noun): The change had a strong effect. Affect (verb): The change will affect performance.

FAQ

How do I remember the difference between their, there, and they're?

Substitute "they are" for they're and "theirs" for their. If neither fits, use there for place or existential uses.

When should I hyphenate a compound adjective?

Hyphenate when two or more words jointly modify a noun before it (a well-known author). Drop the hyphen after the noun: the author is well known. If unsure, check a current dictionary.

What's the fastest way to fix subject-verb agreement?

Find the grammatical subject first (who/what does the action), ignore interrupting phrases, then pick the verb that agrees in number.

Are contractions like you're acceptable in work emails?

Yes for internal and conversational emails. For formal reports or external documents, avoid contractions unless you intentionally want a conversational tone.

How can I check preposition usage quickly?

Search examples of "verb + preposition" in a trusted source or use a grammar tool. Over time you'll memorize common pairings like depend on, interested in, good at.

Try one sentence now

Paste a sentence into the checker above, then apply the five-step rewrite process. Keep a short file of corrected sentences and common patterns to paste into similar messages and speed future edits.