Top 10 Grammar Rules You Can’t Believe You Didn’t Learn

Top 10 Grammar Rules You Can't Believe You Didn't Learn Until UniversityGrammar is an exhaustive subject, with layers of rules from the basic to the obscure. Teaching styles have changed over the past century, and common rules your grandmother learned through memorization and practice could be a mystery to younger generations encouraged to stray from those rules and let their creativity flow. Below are the top 10 grammar rules that you may not have learned until university.

1. A comma and a coordinating conjunction should be used to combine two independent clauses.

What do you call a series of ideas linked by only a comma? A run-on sentence (or comma splice)! This mistake runs rampant in academic writing, regardless of how well the writer thinks he or she knows English. Even worse is that a lot of people are not taught the difference between independent and dependent clauses before attending university, when writing—and writing well—becomes a fact of life.

How detrimental is the comma splice? Run-on sentences detract from the readability and flow of any writing. Arguments can quickly become convoluted and incomprehensible when too many ideas are introduced in one long sentence. When writing needs to be clear and concise, thoughts should be organized using punctuation in all the right places.

Do this:

Holiday shopping is stressful for a lot of people, but some families budget for it.

Not this:

A snowy, cold winter is common in Canada, people sometimes have a hard time keeping up with shoveling, there are storms when the snow gets so high that you cannot make it out of your driveway for days!

2. A semicolon is most often used to separate two independent, closely related clauses.

The rules for using a semicolon are clearly unknown to many people who reach the university level. Writers use this commonly misunderstood form of punctuation in haphazard, mysterious ways. A semicolon is often mistaken for a colon, is used in place of the comma, or even appears at the end of sentences in truly odd situations.

Do this:

Reality TV is a favorite pastime for many people; however, those who hate reality TV have a lot of complaints.

Not this:

Reality TV is a favorite pastime for many people. However; those who hate reality TV have a lot of complaints.

3. A colon is used after a complete sentence to introduce a word, phrase, clause, list, or quotation.

The colon, often mistaken for or incorrectly replaced with the semicolon, has several uses that remain elusive to many writers. The colon is all too often forgotten completely or found in the wrong places at the wrong times.

Do this:

We must remember to buy the following groceries: eggs, milk, flour, and apples.

Not this:

We must remember to buy the following groceries eggs, milk, flour, and apples.

4. A list or comparison of equally significant ideas should use the same grammatical pattern.

Items in a series need to have a parallel structure that uses equal grammatical units. This means that nouns should follow nouns, and subordinate clauses should follow subordinate clauses. If you use a certain form of a verb in each segment of the series, it should be the same in each segment.

Do this:

Her car needed its tires rotated, oil changed, and windshield wipers replaced.

Not this:

Her car needed its tires rotated, oil changing, and its windshield wipers to be replaced.

5. Do not split your infinitives in formal writing.

The infinitive split is a common grammatical mistake that many people don’t even realize they are making. An infinitive is the most basic form of a verb that is not bound by a particular subject or tense, as in “to type.” What writers often do is insert a modifier between the “to” and its accompanying verb—a definite grammar no-no in formal writing (although this rule is disputed in more casual writing). To keep sentences clear, never split your infinitives.

Do this:

I’ll need my best tennis shoes if I’m going to run quickly.

Not this:

I’ll need my best tennis shoes if I’m going to quickly run.

6. A hyphen connects, an en dash separates numbers in a sequence, and an em dash offsets nonessential information from the rest of a sentence.

Where were you when you discovered that a dash isn’t just a dash and that a hyphen belongs in a particular place and not in others? Really, there are three separate forms of punctuation that all look like a dash: the hyphen (-), the en dash (–), and the em dash (—). A hyphen is used to connect compound adjectives, such as blue-green, or compound verbs, such as freeze-dried. It is also used in modifying compounds when modifiers come before a noun, such as high-speed connection.

En dashes, however, are the proper punctuation to use when displaying a range of numbers, like so: 5–10. Em dashes can be used much like a comma to offset nonessential information—information that doesn’t change the meaning of the sentence but does add description.

7. Adjectives modify nouns; adverbs modify verbs, adjectives, and other adverbs.

The difference between an adjective and an adverb seems lost on many writers who never learned the grammatical difference. An adjective is a word that modifies only a noun, whereas an adverb is a word that usually ends in “ly” and modifies verbs, adjectives, and other adverbs. Knowing these differences is important when you need to keep your writing concise, as most adverbs can be removed from a sentence without changing the meaning.


The large, purple flowers on the orchid were wilting.


The large, purple flowers on the orchid were slowly wilting.

8. “I.e.” stands for “that is,” and “e.g.” stands for “for example.”

Many people believe that i.e. and e.g. can be used interchangeably. Both are abbreviations of Latin terms, but each is used in a specific situation. The first, i.e., stands for the Latin term id est, whereas e.g. stands for exempli gratia. I.e. should be used to offer more information or to restate an idea, and e.g. should be used to include an example.


“There are three main methods of motor transportation in the city (i.e., if you can’t afford taxis, try the subway or bus).”


The bake sale included a huge variety of treats (e.g., cookies, pies, cakes, and pastries).

9. Explain an acronym in full the first time it appears. Every usage afterward should be the acronym.

Acronyms can also be mysterious to a writer who doesn’t know the correct grammatical usage. Just remember, an acronym needs to be written out fully the first time it appears in a writing and then used consistently throughout the rest of the writing each time the term appears.

First use:

The Society for the Prevention of Cruelty to Animals (SPCA) was founded in England in 1824.

Second use:

The SPCA is dedicated to protecting animal welfare and finding homes for unwanted animals.

10. A modifier (a word, phrase, or clause that describes something else) goes next to the thing it modifies.

Misplacing your modifier can lead to some very confused readers. A sentence can sound awkward or the meaning can be changed completely if a word, phrase, or clause is separated from the word it describes.

Do this:

I picked up my new hamster, Bert, who was small and fluffy.

Not this:

Small and fluffy, I picked up my new hamster, Bert.

Even if you didn’t learn them until university, remembering these top 10 grammar rules is sure to strengthen your writing and help you earn better grades. To enhance your grammar skills even further, consider taking an online grammar training course, such as GrammarCamp.


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