Word processing programs usually come prepared to help you with built-in grammar checks, but you should have a basic knowledge of the English language to make your writing flow and read smoothly.
There are probably over one hundred rules of grammar so finding a consensus on the number one rule is unlikely. I found sources that agree on 11 basic rules for English grammar – see 11 Rules of Writing, Grammar, and Punctuation and 11 Essential Rules of Grammar. YourDictionary also has an excellent discussion of Basic English Grammar Rules. They also provide an infograph of the Top 10 Grammar Errors.
Some of the most common grammatical mistakes writers make fall into two categories: Technicalities and Punctuation or Word Confusion. Here are some of the most common mistakes in each category.
Technicalities and Punctuation
Improper use of the apostrophe – This is such a common problem that there is actually a cause on Causes.com to Stop Improper Use of the Apostrophe and a website to Free the apostrophe. Basically, the apostrophe is used to show possession or to indicate the omission of letters or numbers. Scribendi has an excellent discussion on the proper use of the apostrophe.
Incomplete Comparisons – An incomplete comparison is a comparison that leaves out one of the items being compared. “My mom is prettier than yours” is an incomplete comparison. Prettier than your what? See the explanation from Grammarly Handbook:
A comparative sentence must clearly identify all the items that are being compared. This will help to ensure the comparison is complete. Complete comparative sentences also help to strengthen the delivery and clarification of the comparison. Below are some examples:
Incomplete Comparison: My car is newer than his.
Complete Comparison: My car is newer than his car.
Comparative sentences often use the words “more” and “most”. When the situation calls for the usage of these words, “than” and “that” must also be used.
Use of commas – This is a topic for an entire blog post, but for now here are the eight basic uses of commas:
- when listing items in succession
- between multiple adjectives that are modifying the same noun
- before conjunctions linking independent clauses
- after introductory words or phrases
- around nonessential clarifying phrases
- with dates and addresses
- when directly addressing someone
- at the salutation and close of a letter
They’re vs. Their vs. There – These three words all have the same pronunciations, but they have entirely different meanings. One is a contraction for “they are” (they’re), one refers to something owned by a group (their), and one refers to a place (there).
You’re vs. Your – You’re is a contraction of you are. Your is the possessive form of you and is used to describe something as belonging to you. If you can replace the word with you are, then use you’re.
It’s vs. Its – It’s is a contraction for it is. Its is a possessive pronoun. If you are not sure which spelling to use, try replacing it with it is. If it doesn’t work in its place, then use its.
Which vs. That – Grammar Girl says that “you use that before a restrictive clause and which before everything else.” So, if the clause doesn’t change the meaning of the sentence, use which and insert commas around the clause.
Affect vs. Effect – In their discussion of affect vs. effect, Grammarist says:
Affect is usually a verb, and effect is usually a noun. To affect something is to change or influence it, and an effect is something that happens due to a cause. When you affect something, it produces an effect.
FYI: Grammarist has a large collection of words that are commonly mixed up and used improperly – Easily confused words