Grammar can be a bit of a minefield, even for native speakers. Often, our brains move faster than our fingers, leading to those "I know better" slips.
Here are the most common culprits that tend to trip people up:
1. The "Big Three" Confusions
These are the most frequent errors found in emails, texts, and even professional documents.
Its vs. It's: * Its is possessive (e.g., "The dog wagged its tail").
It's is a contraction for "it is" or "it has."
Their, There, and They're:
Their is possessive (belonging to them).
There refers to a place or a point.
They're is a contraction for "they are."
Your vs. You're:
Your shows ownership (e.g., "Your coffee is cold").
You're is a contraction for "you are."
2. Punctuation Pitfalls
Misplaced punctuation can change the entire meaning of a sentence.
The Comma Splice: This happens when you join two independent sentences with only a comma.
Error: "I love cooking, I do it every day."
Fix: Use a period, a semicolon, or a conjunction like "and."
Apostrophe Catastrophes: Adding apostrophes to make words plural is a no-go.
Error: "Apple's for sale."
Fix: "Apples for sale." (Save the apostrophe for possession or contractions).
3. Tricky Word Pairings
Some words sound so similar that we swap them without thinking.

Word Pair	The Difference
Affect vs. Effect	Affect is usually a verb (to influence); Effect is usually a noun (the result).
Lose vs. Loose	You lose a game; your pants are too loose.
Then vs. Than	Then relates to time; Than is used for comparisons.
Complement vs. Compliment	A complement completes something; a compliment is a nice remark.

4. Subject-Verb Agreement
The verb must always match the "number" of the subject.
The Error: "The list of items are on the desk."
The Fix: "The list of items is on the desk." (The subject is "the list," which is singular, not "items").
Pro-Tip: If you're unsure about a contraction, say the full words out loud. If "The dog wagged it is tail" sounds wrong, then you know you shouldn't use the apostrophe!