Levels of Formality and Slang and Idioms


  • Understand levels of formality
  • Recognize slang and idioms.
  • Learn to avoid using slang and idioms in formal writing.

Words are the basis of how a reader or listener judges you, the writer and speaker. When you write an academic paper or speak in a business interview, you want to be sure to choose your words carefully. In our casual, everyday talk, we often use a lot of “ums,” “likes,” “yeahs,” and so on. This everyday language is not appropriate for formal contexts, such as academic papers and business interviews. You should switch between different ways of speaking and writing depending on whether the context is formal or informal.

Each of us adapts in some way depending on who we’re speaking to.  You would probably talk very different to your mother versus your best friend versus your boss.  In the same manner, think of the written language as something that also should adapt according to its purposes and who its speaking to.  Academic English, though not the most formal out there, tends to be more formal than say, a magazine article, and most definitely more so than an email or text.  So here are some ways to think about these different levels of formality:

Informal Style

Use this when writing to a very limited audience—yourself, a close friend, a classmate—in short notes or personal letters.  Informal writing is colloquial and may contain slang or fragments.

Example: Most dudes in my college fraternity seem to be pretty brainy, and they hit the books real hard.  But they aren’t that stuck up, not like the Geek Patrol we knew at Jefferson High.  In fat, they’re all right.  They even tutor kids whose grades are tanking.

Familiar/Popular Style

Use in short business memos, letters to the editor, friends, or relatives.  Familiar writing resembles everyday conversation but does not use colloquialisms, slang, or fragments.

Example: You would like the students in my fraternity.  They are fairly smart, but they often burn the midnight oil when they want to ace a big exam.  However, they’re not snobby eggheads.  In fact they often tutor other kids who are having trouble with school work.

Formal Style

Use when writing academic papers, essay questions, business letters or business reports.  It is usually highly stylized and uses no colloquialisms, slang, or clichés.  There is no addressing of the reader by using “you.”  Also, more formal vocabulary is used as well as more complex sentence structure.

Example: Students in my fraternity are quite likable.  They are intelligent, but they are also diligent, studying hard especially when it comes to major examinations.  However, they are not snobs.  In fact they often tutor other students who are having difficult with their studies.

For most academic papers, you should aim to write in the formal style.  Most of us tend to write more in the familiar style and consider that formal, but academic writing should not have the colloquial, everyday speech feel of familiar style.


Hey guys, let’s learn about slang and other cool stuff like that! It will be awesome, trust me. This section is off the hook! What do you notice about the previous paragraph? You might notice that the language sounds informal, or casual, like someone might talk with a friend or family member. The paragraph also uses a lot of slang. Slang is a type of language that is informal and playful. It often changes over time. The slang of the past is different than the slang of today, but some slang has carried over into the present. Slang also varies by region and culture. The important thing to understand is that slang is casual talk, and you should avoid using it in formal contexts. There are literally thousands of slang words and expressions. Table 5.17 “Slang Expressions” explains just a few of the more common terms.

Table 5.17 Slang Expressions

Slang Word or Phrase Meaning
check it out, check this out v. look at, watch, examine
chocoholic, workaholic, shopaholic n. a person who loves, is addicted to chocolate/work/shopping
stuff n. things (used as a singular, noncount noun)
taking care of business doing things that need to be done
pro n. a person who is a professional
crack up v. to laugh uncontrollably
veg (sounds like the veg in vegetable) v. relax and do nothing
dude, man n. person, man
all-nighter n. studying all night
cool adj. good, fashionable
gross, nasty adj. disgusting
pig out v. eat a lot, overeat
screw up v. make a mistake
awesome adj. great

Exercise 1

Edit the business e-mail by replacing any slang words and phrases with more formal language. Dear Ms. O’Connor: I am writing to follow up on my interview from last week. First of all, it was awesome to meet you. You are a really cool lady. I believe I would be a pro at all the stuff you mentioned that would be required of me in this job. I am not a workaholic, but I do work hard and “take care of business.” Haha. Please contact me if you have any questions or concerns. Sincerely, M. Ernest Anderson


Idioms are expressions that have a meaning different from the dictionary definitions of the individual words in the expression. Because English contains many idioms, nonnative English speakers have difficulties making logical sense of idioms and idiomatic expressions. The more you are exposed to English, however, the more idioms you will come to understand. Until then, memorizing the more common idioms may be of some help.

Table 5.18 Idioms

Idiom Definition
a blessing in disguise a good thing you do not recognize at first
a piece of cake easy to do
better late than never it is better to do something late than not at all
get over it recover from something (like a perceived insult)
I have no idea I don’t know
not a chance it will definitely not happen
on pins and needles very nervous about something that is happening
on top of the world feeling great
pulling your leg making a joke by tricking another person
the sky is the limit the possibilities are endless

What if you come across an idiom that you do not understand? There are clues that can help you. They are called context clues. Context clues are words or phrases around the unknown word or phrase that may help you decipher its meaning.

  1. Definition or explanation clue. An idiom may be explained immediately after its use. Sentence: I felt like I was sitting on pins and needles I was so nervous.
  2. Restatement or synonym clues. An idiom may be simplified or restated. Sentence: The young girl felt as though she had been sent to the dog house when her mother punished her for fighting in school.
  3. Contrast or Antonym clues. An idiom may be clarified by a contrasting phrase or antonym that is near it. Sentence: Chynna thought the 5k marathon would be a piece of cake, but it turned out to be very difficult.

Pay attention to the signal word but, which tells the reader that an opposite thought or concept is occurring.

Key Takeaways

  • Informal language is not appropriate in formal writing or speaking contexts.
  • Slang and idioms might not make logical sense to nonnative speakers of English.
  • It is good to be aware of slang and idioms so they do not appear in your formal writing.