Formal Versus Informal English: 6 Key Differences

Like many languages, English has a formal and informal register (how a language is used in different situations). Knowing the differences between the two can significantly improve your level of fluency.

So how do you, say, talk to a superior versus a close family member in English? We cover all that (and more) in the post below.

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The Difference Between Formal Versus Informal English

• Formal English is the standard and polished form of English used in academic, business and similar contexts (like communications from the government, for example). You use it for people in a higher position than you (like your teacher or boss) or complete strangers—as well as academic or business writing, interviews and presentations.
• Informal English is used in everyday conversations and written communication in places like social media. You use it with family members, friends and peers (people who are your social equals) in casual settings. 

Here are some formal English phrases you can use and their informal counterparts:

As you can see from the video, formal English uses correct grammar and vocabulary appropriate for the context. Meanwhile, informal English uses contractions, colloquialisms, slang and the like.  

In case you’re wondering what “contractions,” “colloquialisms” and “slang” are, you’re in luck: that’s what we’ll cover in the next sections.

Features of Formal and Informal English

1. Contractions

Contractions are common in informal language. Usually, they are two words merged together and are characterized (differentiated from others) by an apostrophe ( ‘ ). 

Here are some of the most common contractions in the English language.

Informal/Contracted Form	Formal Form
can't	cannot
don't	do not
shouldn't	should not
couldn't	could not
won't	will not
isn't	is not
aren't	are not
didn't	did not
hasn't	has not
haven't	have not
he's/she's	he is/she is
they're	they are
it's	it is
it'll	it will
it'd	it would

2. Phrasal Verbs

A phrasal verb is an idiomatic phrase that consists of a verb and another element, typically an adverb or preposition. Phrasal verbs are more common in informal contexts than formal ones.

Here are some examples:

Phrasal Verb	Definition	Example Sentence
speak up	speak more loudly	I couldn't hear what he said, so I asked him to speak up.
turn down	refuse	I can't turn down an invitation from my boss.
find out	discover	If my parents find out what I did, they won't be happy.
got away	escape	He left the door open, and one of the hamsters got away.
run into	to meet suddenly	I didn't expect to run into my friend at the mall, but I did.
set off	begin a journey, start	Bilbo Baggins set off for his journey into the kingdom of Erebor.
break up	end a relationship	They had such a good relationship that I didn't expect them to break up.
check (somebody/something) out	look at them/it closely	Check out that new restaurant down the block!
give up	quit, surrender	I will never give up on my dreams.
look after	take care of, watch over	He looks after his nephew while his brother is at work.
put off	postpone, delay	The meeting was put off until next Thursday.
work out	find a solution	I will try to work something out to solve our budget problems.
come across	appear	He comes across as quiet, but he actually likes to laugh out loud.
bring up	mention, introduce a topic	You should bring up that idea in our next meeting. It sounds great!
get along	have a good relationship	We live in the same house, so we should all get along.

3. Colloquialisms and Slang

Colloquialisms and slang are words and phrases regarded as very informal and rarely used in written speech. They typically vary between groups of people, regions, professions or age groups. 

In the English-speaking world, Americans use different slang from Brits (slang word for people from Britain) and Aussies (slang word for people from Australia), such as:

Colloquialism/Slang	Definition	Example Sentence
dude	friend (usually male)	Dude, what is happening to you?
buck	American dollar	How many bucks do you have left?
zonked	tired, exhausted	Working 16 hours a day for five days straight left me zonked.
chill out	relax	You should chill out after working 16 hours a day for five days straight.
sweet	good, awesome	Sweet, thank you for the birthday present!
bail	leave/depart quickly	I need to bail; the bus is leaving in five minutes.
hella	very, extremely	The sushi from that new restaurant was hella good.
freak out	become agitated/anxious	My friend doesn't freak out even under pressure.
hang out	spend time together casually	Do you want to hang out sometime?
kiddo	informal term of endearment for a child or younger person	Kiddo, trust me: I know what it's like to be in your position.
no biggie	no big deal, not a significant issue	No biggie if you can't come tomorrow. I'm also free next week!
y'all	contraction of "you all"	Y'all won't believe what just happened to me!
sick	amazing, awesome	Dude, that rock concert was sick!
lotta	contraction of "lot of"	My favorite Led Zeppelin song is "A Whole Lotta Love."
dunno	contraction of "don't know"	I dunno where Anne went.

4. Idioms

To paraphrase (explain in my own words) the definition from the Merriam-Webster dictionary, an idiom is an expression in which you can’t easily guess the actual meaning from the words used.  

Here are examples of idioms commonly found in informal conversations:

Idiom	Definition	Example Sentence
take a rain check	politely refusing an offer	Sorry, I'll have to take a rain check regarding tonight's dinner.
get the cold shoulder	to be treated in an unfriendly way	Please don't give me the cold shoulder. Talk to me.
spill the beans	to reveal a secret	Come on. Spill the beans about what's really going on with Lucy.
go Dutch	to pay for one's own food or drink	I don't have enough money, so you guys will have to go Dutch for tonight's dinner.
a piece of cake	easy, effortless	She's a smart girl, so most school subjects are a piece of cake for her.
break the ice	to start a conversation	Since we're all new here, let's break the ice!
on the same page	to have the same understanding about a matter	I want to make sure we're all on the same page regarding this project.
cut to the chase	get to the point, skip unnecessary details	It's better to cut to the chase than to talk on and on without getting anywhere.
cry over spilled milk	to get sad or upset about a mistake that cannot be reversed	There's no use crying over spilled milk.
blessing in disguise	something that looks negative but has a positive outcome	Missing the bus was a blessing in disguise because I met the love of my life at the bus stop.
take it with a grain of salt	to not believe something completely	John is a liar, so take anything he says with a grain of salt.
break a leg	good luck	Break a leg at tomorrow's competition!
needle in a haystack	something that is hard to find	Looking for a ring that fell into the ocean is like looking for a needle in a haystack.
under the weather	sick	Sorry I can't come to the party tonight. I'm feeling under the weather.
kill two birds with one stone	to accomplish two things at the same time	Talking a walk helps me relax and enjoy nature—killing two birds with one stone.

5. First-person Pronouns

In informal contexts, first-person pronouns (I and we) are more frequently used—this makes for sentences that use the active voice. On the other hand, you’ll typically see passive voice in formal settings, particularly in official or academic writing. 

Here are examples of sentences using first-person pronouns, along with their more formal versions. Notice how different they come across, even though they say the same thing!

Active Voice/Informal Form	Passive Voice/Formal Form
We asked the students to complete a survey.	The students were asked to complete a survey.
I need to finish this report by Friday night.	The report must be finished by Friday night.
We need to write a letter to the supervisor.	A letter must be written to the supervisor.
We will give incentives to those who have exceptional performance.	Those who have exceptional performance will be given incentives.
I will send you the draft next week.	The draft will be sent next week.
We will launch a new product within the next six months.	A new product will be launched within the next six months.
I will create a report for the board of directors.	A report will be created for the board of directors.
We will fill out these forms and send them to HR.	These forms will be filled out and sent to HR.
I will change your order to a different one.	This order will be changed to a different one.
I appreciate your thoughts on the matter.	Your thoughts on the matter are appreciated.
We will hold the meeting on Wednesday.	The meeting will be held on Wednesday.

6. Everyday Phrases in Formal and Informal English

If you want more examples (and need some handy phrases you can use for friends versus your boss), here’s another table for you!0

And if you want to see these phrases in action, you can browse any of the videos from FluentU‘s library.

 

Learning the differences between formal and informal English will go a long way in improving your grasp of the language. The better you master words and phrases from both registers, the more natural your speech will sound and the more confident you’ll feel!