Formal and Informal English Words and When to Use Them

Imagine you want to tell your manager that you would like a copy of a report. You could write any of these:

• "Can I get a copy of the report?"
• "Could I have a copy of the report, please?"
• "I would like to request a copy of the report."

All three are correct English. Yet they do not feel the same. The first is relaxed, the second is polite and neutral, and the third is formal enough to appear in an official letter. Picking among them is not a matter of grammar. It is a matter of vocabulary and tone, and learners often find it harder than learning new words in the first place.

What register means

The British Council's TeachingEnglish site explains that register often refers to the degree of formality of language. More broadly, the word can mean the language used by a group of people with shared work or interests, such as doctors or lawyers. In this post we use the first meaning.

The same page gives a pair of examples. "Would you mind passing the salt?" suits a formal situation with someone you do not know well. "Pass me the salt" fits a conversation between friends, although it could sound rude in the wrong setting. It also mentions that language teachers often divide this into three groups: formal, neutral and informal.

That three-part idea is a handy way to think about it. Neutral language is the safe middle. It is what you would say to most people in most situations. Formal and informal are moves away from it in either direction.

Appropriacy matters more than a label

Another TeachingEnglish article prefers the term appropriacy to register. The author's point is that what is suitable depends on the words you choose, how you say them and the situation you are in, including who is listening. The article gives an example: "Shut up!" said to a friend in a pub, with a smile and the right intonation, can mean something like "I don't believe you." Said coldly to a stranger or at a formal dinner, it is plainly rude.

The same article notes that appropriacy is learned over years, differs between cultures, and is easy to get wrong without realizing. It also says that native speakers may not notice when a learner lacks it, which means you can go a long time without feedback. The practical lesson is to pay attention to who you are talking to and what the situation expects, instead of relying on a word list alone.

Common word pairs

Here are some everyday pairs, from informal to formal. Treat them as tendencies, not strict rules. Real usage varies.

Notice two things. First, many words in the neutral column are the same as the informal one. A word like buy is perfectly acceptable in most situations. Second, the formal choices often come from Latin or French roots, and tend to be longer. That is a tendency, not a rule, but it gives you a clue when you meet an unfamiliar word in a formal text. If you are interested in those roots, there is a good introduction in Greek and Latin roots in English.

Phrasal verbs and idioms

Phrasal verbs, such as put off, find out and look into, tend to feel more informal than single-word equivalents like postpone, discover and investigate. Idioms often do too. In a formal report, you would probably write "postpone the meeting" and not "put off the meeting." In a chat with a colleague, "let's put it off until Thursday" sounds perfectly natural.

This does not mean phrasal verbs are always casual. Many are neutral and used everywhere, like turn on or fill in. Treat the idea as a guide, and notice what the writers and speakers you respect actually do. For business settings in particular, common business idioms covers phrases you will hear at work.

Choosing the right level

A simple method works in most situations. Ask three questions.

1. Who is the reader or listener? A friend, a colleague, a customer, a teacher, an official?
2. What is the setting? A text message, an email, a formal letter, an exam essay, a conversation?
3. What do I want to achieve? To be friendly, to be clear, to be respectful, to sound authoritative?

If you are unsure, aim for neutral. The TeachingEnglish article on appropriacy recommends teaching neutral forms first, because they are the safest and most widely useful. That is good advice for a learner too. You will rarely cause offense by being neutral, and you can move up or down from there once you are confident.

Practicing the shift

The TeachingEnglish article suggests practicing by shifting a sentence between formal, neutral and informal versions. You can try this on your own.

Take a sentence you wrote today and rewrite it twice: once as if for a close friend and once as if for a senior person you have never met. Notice which words change. Some will be vocabulary, such as get becoming obtain. Others will be structure, such as adding could or would to soften a request.

Over a few weeks, you will build an instinct for it. Reading helps too. When you read an email, a news article and a message from a friend, notice how the word choices differ, even when the topic is the same.

Two mistakes to avoid

Using formal words to sound clever. Learners sometimes pack a message with long, formal words in the hope of sounding more advanced. The result is often stiff or slightly comic, like a text message that reads "I shall commence the journey presently." Clear and neutral almost always reads better than impressive and awkward.

Mixing levels in the same text. A sentence that starts formally and ends with slang jars the reader. "I would be grateful if you could send the file, because I am totally swamped" is an example: the first half is polite and formal, the second is casual. Neither half is wrong, but together they feel uneven. When you edit, read the text aloud and listen for a word that sounds like it came from a different conversation.

Using this with your vocabulary study

When you learn a new word, note its level. A word may be fine in an essay but odd in conversation, or the reverse. If you write obtain in a chat with a friend, they may smile.

If you use Wordabulary, the usage note on a word page, where there is one, is a good place to look for hints like this. When you add a new word to your own notes, add a short tag such as "formal" or "casual," and a simple example sentence from a real source.