Formal and Informal Language: Conventions and When to Use

In writing, context means everything. Depending on a writing task’s audience, occasion, and purpose, the audience’s expectations for that task will vary, along with the appropriate writing conventions. An experienced writer remains aware of the writing context and its expectations for any particular writing task, and uses language accordingly. This means that a skillful writer knows how and when to differentiate between formal and informal language.

Formal language: language that follows or accords to established form, custom, or rule

Example sentences using formal language:

• Those reading Slaughterhouse-Five feel caught off guard when they first encounter narrator Billy Pilgrim’s tone.
• According to psychologist Erik Erikson, as a human progresses from infancy through old age, they undergo a stage-by-stage succession of social impulses and learnings that frame how they view the world, their relationships and interactions, and their goals.
• The Niger River, the principal river of West Africa, flows 2600 miles and plays a critical role in the region’s ecological function.
• Investors new to the stock market, particularly technology stocks, might feel overwhelmed by the market’s volatile nature.
• We regret to inform you that your company has reached a point of liquidation.

Informal language: language characteristic of or appropriate to ordinary, casual, or familiar use

Example sentences using informal language:

• I read Things Fall Apart by Chinua Achebe, and Okonkwo was such an alpha, no cap fr fr.
• Carl Jung basically tells us that our dreams have crazy power to show us our subconscious state, bro.
• Have you seen how wild the Amazon River gets? Dude, that river straight wildin’!
• Stock market newbies get all riled up when they see the market dip like a cookie in some milk.
• Your company just got rekt.

Compared to informal language, formal language contains more complex sentences, objective and direct language, and technical or specific terminology. This article will overview the differences between formal and informal language, explaining what changes depending on the context’s formality.

Overview: Formal vs. Informal Language

Formal Language

Usually found in professional and academic interactions, formal language tends to adopt objective and proper conventions. Formal tone, word choice (diction), and sentence structure (syntax) usually favors complexity over simplicity, directness over abstractness, seriousness over lightheartedness, literal expressions over figurative ones, bookish terminology over colloquial, and full references instead of abbreviated references. 

Informal Language

Typically used in casual situations, like friendly or intimate communication, informal language tends to feature lax, imperfect conventions. Opposing those of formal language, the tone, diction, and syntax of informal language usually favor simple and sometimes incomplete sentences, the use of expressions and idioms, a more lighthearted or emotional tone, colloquial phrasing, and shorthand references like abbreviations and acronyms.

Key Differences between Formal and Informal Language Conventions

Keep in mind that these patterns provide a general rule of thumb, but each writing task’s context has unique demands, depending on audience, situation, occasion, and writing purpose. 

1. Tone

Tone: the general emotional attitude of a text, writing, or situation

General tone: More serious and balanced in formal writing, more lighthearted (or emotional) in informal writing

Formal language tends to keep a conservative, professional, emotionally neutral tone, in order to preserve a stable mood. Excessively excited, angry, happy, or sad tones come across as unrestrained, which contradicts the composed nature of a formal environment, such as academia or the workplace, where the writer’s audience expects the writer to give objective, analytical, or informative content.

On the other hand, informal language reflects the emotions that humans express in intimate communication. Audiences in informal contexts like casual emails, text messages, or lunchtime conversation with friendly coworkers, will respond more expectantly to the direct expression of emotions such as amusement, anger, or sadness.

Formal tone: That meeting brought up some of our strategy’s critical shortcomings, which we should revisit next time.
Informal tone: Dang, that meeting was so rough! I almost cried when they shot down my proposal to move to 49th Street. 

Formal tone: In To Kill a Mockingbird, when Jem chops the buds off all Mrs. Dubose’s camellia flowers, he signals a desperation to gain some control over his environment, which he sees degrading in contrast to his own morals.
Informal tone: Go Jem! I was pumped when he chopped those flowers, because Mrs. Dubose was racist, and Jem’s just a kid.

Familiarity: More professional and detached in formal writing, more familiar and personal in informal writing

Formal writing aims to maintain a professional distance from the reader in both content and writing conventions (tone, syntax, diction), generally choosing not to mention anything personal, aggressive, or defamatory. Including these volatile sentiments in writing risks the audience viewing the text as petty, uncomfortable, biased, or uncontrolled, and therefore unprofessional. In contrast, a formal-setting writer aims to remain objective, analytical, and level-headed. 

The audience in informal or personal settings, on the other hand, expects the writer to let their guard down somewhat, because the audience in personal contexts usually knows the writer more intimately. Texting a friend, for example, provides an acceptable situation for a writer to mention personal sentiments like gossip, emotional disturbances, physical maladies, and the like.

Formal tone: Making chili at home can be enjoyable and surprisingly simple: It requires olive oil, beef, an onion, chili powder, tomatoes, and kidney beans.
Informal tone: I love me some chili, but my wife doesn’t always like when I eat it–if you know what I mean.

Formal tone: Genghis Khan, the first great Khan of the Mongol Empire, had a rough childhood. He had to hunt and forage for his food and is rumored to have murdered his half-brother in a dispute over a meal.
Informal tone: Genghis Khan had a surprisingly vicious childhood and may have even killed his brother over a food dispute, which is pretty messed up, if you ask me.

2. Vocabulary/Diction

Diction: the choice and use of words or phrases in writing or speech

Diction refers to a writer’s word choice–the words and phrases that a writer selects to convey their ideas. Depending on the writing context, including the audience and occasion, we make different choices in regard to our diction.

Phrasal verbs: No in formal writing, yes in informal writing

Informal writing contexts, such as texting a friend or sending a friendly email to a coworker, often utilize phrasal verbs, those verbs that include a preposition or adjective: put down, hang out, fall down, go to, look down on, put up with, carry on, get up, etc. Phrasal verbs work well in conversation because they’re simple and easy to understand with vocal voice inflection.

Formal writing contexts avoid phrasal verbs because non-phrasal verbs usually offer clearer meaning than do phrasal verbs, which usually have vague or double meanings. For example, if I say He put down his friend, the phrasal verb put down could mean the subject insulted his friend, or the subject literally placed his friend on the ground. If I say He insulted his friend, the single-word verb insulted offers a clearer expression of what I mean. Since precision and clarity take priority in formal writing, regular/non-phrasal verbs reign supreme in formal contexts.

Formal verb: The boy in Paolo Coelho’s The Alchemist develops his emotions.
Informal verb: The boy in Paolo Coelho’s The Alchemist works on his emotions.

Formal verb: All indicators suggest that stocks will increase in November.
Informal verb: All indicators suggest that stocks will break out in November.

Contractions: No in formal writing, yes in informal writing

Contractions, the shortened form of a word with an apostrophe in place of omitted letters, are commonplace in speech: can’t, won’t, that’s, how’ve, etc. People use contractions frequently in speech because they offer a convenient shortcut, saving syllables without compromising meaning. Since informal writing tends to be more conversational, it adopts many of the same conventions as speech–the usage of contractions included.

Formal writing, however, avoids contractions because they come across as lazy–contractions are linguistic shortcuts, after all.

Formal language: Hello Mr. Williams, how have you been?
Informal language: Hello Mr. Williams, how’ve you been?

Formal language: When plaque clogs someone’s arteriole, blood and therefore oxygen cannot reach the tissues as easily.
Informal language: When you’ve got a clogged arteriole, blood and oxygen can’t reach the tissues as easily.

Colloquial language: No in formal writing, yes in informal writing

Commonly used in speech, colloquial language includes idioms and cliche phrases (piece of cake, no brainer, out of your mind) as well as colloquial terms (what’s up, dude, diss, swag). Not only do these terms signal casual and friendly conversation due to the fact that they directly address audience members, but they risk the possibility that readers won’t understand them. For example, many cultures around the world use neither the word dude nor the phrase You’re out of your mind. Since informal writing usually assumes a relatively familiar relationship between writer and audience, it provides a more suitable context for colloquialisms and idioms than formal writing does.

Formal writing avoids using colloquial language and cliche phrases in order to ensure that readers understand what the text is trying to say.

Formal language: In Aldous Huxley’s Brave New World, John the Savage leaves the World State seeking a home that satisfies his need for passion.
Informal language: In Aldous Huxley’s Brave New World, John the Savage ditches the World State because he’s fed up with their lack of true passion.

Formal language: Stephen Curry’s shooting percentage has fallen 7% from last season.
Informal language: Steph Curry’s shooting percentage has been trash compared to previous seasons.

First-person pronouns: No in formal writing, yes in informal writing

Formal writing generally avoids first-person pronouns, such as I, me, you, us, we, etc. Since these terms give the text a personal and therefore subjective tone, formal writing situations–like academic papers, reports, and professional updates–avoid using them, in order to maintain an objective and analytical tone.

Still, there are some formal situations that naturally invite (or even require) the use of a first-person pronoun. In these cases, avoiding the first person makes the text awkward and confusing. For example, if an employee is emailing her whole company to update them on her visit to a corporate conference, she might contextualize the message by beginning, “Over the past week, a few coworkers and I visited New York.” Even though a company-wide email is a formal writing situation, the author’s direct involvement with the information makes the first-person pronoun acceptable.

If you find yourself in a formal writing context, debating using first-person pronouns or not, evaluate the language’s clarity versus the writing occasion’s formality: Clarity should always take priority over formality, but the ultimate goal is to honor both. 

Formal tone: Hey Sandra, I heard you are unable to attend our meeting today.
Informal tone: Yo, I heard you can’t make it today?

Formal tone: In the movie Top Gun, the death of Maverick’s friend, Goose, sends Maverick into an emotional unraveling, from which he rescues himself throughout the movie.
Informal tone: When you see Goose bite the dust upon ejection from that Jet, you know it’s only a matter of time before the protagonist Maverick makes a comeback.

Formal tone: A living organism’s cell strives to maintain a mineral balance, keeping potassium, sodium, magnesium, calcium, and other minerals in appropriate ratios inside and outside of the cell.
Informal tone: Your body’s cells work on keeping a balance between the minerals inside and outside of the cell.

3. Grammar/Syntax

Syntax: the arrangement of words and phrases to create well-formed sentences

Sentence length: longer in formal writing, shorter in informal writing

Since formal and informal situations usually involve different goals and occasions, sentence length tends to reflect those differences: formal communication usually aims to convey an analytical or evaluative idea, while informal communication often seeks to convey basic information, emotions, or thoughts. Since analytical and evaluative ideas require specificity and sufficient support or evidence, these ideas often require not only more-specific words, but longer sentences in order to adequately and fully convey the writer’s perspective.

Sentence complexity: more complex in formal writing, less complex in informal writing

Sentence complexity refers to sentence structure, with more complex sentences having more phrases and clauses between periods: This is a simple sentence. This one, on the other hand, with commas and dependent clauses separated by commas, is a much more complex sentence.

Formal writing tends to have more complexity, due to the reader’s expectations and the analytical nature of formal writing scenarios. In a formal context, such as academia or the professional workplace, the audience often evaluates the writer and their ideas for a variety of possible reasons: to assess the writer’s value to the company, to make an important decision about the company’s direction, to learn from the writer, or to give the writer a score or grade (as in academia). Under these expectations, the writer must remain precise and thorough, to adequately convey their nuanced idea without risking oversimplifying it. To achieve precision and thoroughness in writing, the writer often needs to utilize more complex sentence structures.

Sentence fragments: Never in formal writing, sometimes in informal writing

This sentence.

See that? No verb, no clause–just a subject. That is an example of a sentence fragment, an incomplete sentence missing either a subject or a predicate. 

Formal writing occasions typically involve a more critical audience. Whole-staff emails, literary analysis, scientific research reports, proposals to the boss–when writing texts like these, the author aims to convey competence. Therefore, formal-context writers use complete sentences to show that they understand proper writing conventions.

On the other hand, when writing a text to a friend, a dialogue in a story, or even an email to a well-known coworker, a writer can sometimes use sentence fragments because the audience isn’t evaluating the writer’s professional competence. However, when in doubt, always use a complete sentence.

Formal syntax: Do you plan to join us at the meeting?
Informal syntax: Coming to the meeting?

Formal complexity: Laurie Halse Anderson’s novel Speak tells the story of Melinda Sordino, a girl who refuses to speak to her peers at school, holding in a secret that the audience later discovers.
Informal complexity: The main character in Speak is Melinda Sordino. She doesn’t talk to anybody at school, but eventually the audience understands why.

Formal syntax: Those shoes have an awesome design.
Informal syntax: Sick shoes.

Wrapping up

No two writing contexts are the same–the audience, the purpose, the assignment, and the occasion change every time you sit down to craft a message. This makes it difficult to generalize any overarching rules about formal vs. informal conventions. Still, in professional and academic contexts, it’s always better to err on the side of caution and formality–using an inappropriately formal tone hurts less than using an inappropriately informal tone.

The more you write, and the more you read, the more intuitively you begin to understand the rules of the page. Over time, you’ll develop an awareness for how to write with formal and informal conventions–and until that point, adopt a learner’s mindset and consult this guide if you ever feel unsure. Keep learning and writing, and you’ll look back one day and think, Wow, I’ve become a fluent writer. Keep going, and write on.