Formal and informal words are used in different situations depending on who you are speaking or writing to. Informal words are common in everyday conversations with friends, family, and people you know well, while formal words are more appropriate for academic writing, business communication, professional emails, reports, and official situations.
For example, “ask” is a common everyday word, while “inquire” is a more formal alternative. Similarly, “help” can become “assist,” and “buy” can become “purchase” in more formal contexts.
Learning common formal and informal word pairs can help you choose vocabulary that matches the situation and communicate more effectively. In this guide, you’ll learn 100+ formal and informal words in English, organized into useful pairs with examples to show how they are used.
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What Are Formal and Informal Words?
Formal and informal words are words that express similar meanings but are used in different situations depending on the level of formality.
Formal words are generally used in professional, academic, business, and official communication. They often make writing sound more precise or professional.
Informal words are more common in everyday speech, casual conversations, text messages, and communication with friends and family.
For example:
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Informal: We need to find out what happened.
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Formal: We need to determine what happened.
Both sentences communicate a similar idea, but “determine” is more suitable for formal contexts.
Here are a few more common examples:
| Informal Word | Formal Word |
|---|---|
| ask | inquire |
| buy | purchase |
| help | assist |
| get | obtain |
| tell | inform |
| need | require |
| show | demonstrate |
| check | verify |
The best word depends on the context. An informal word is not necessarily incorrect, and a formal word is not always better. Effective English means choosing the level of formality that suits your audience and situation.
Formal and Informal Words List
The following list contains common formal and informal words in English. The informal words are frequently used in everyday communication, while their formal alternatives are often more suitable for academic, professional, business, and official contexts.
| Informal Word | Formal Word |
|---|---|
| ask | inquire |
| answer | respond |
| buy | purchase |
| check | verify |
| choose | select |
| end | conclude |
| enough | sufficient |
| fix | repair |
| get | obtain |
| give | provide |
| help | assist |
| keep | retain |
| leave | depart |
| need | require |
| say | state |
| show | demonstrate |
| start | commence |
| tell | inform |
| use | utilize |
| wrong | incorrect |
| right | correct |
| cheap | inexpensive |
| costly | expensive |
| whole | entire |
| mainly | primarily |
| maybe | perhaps |
| lucky | fortunate |
| better | superior |
| worse | inferior |
| job | occupation |
| chance | opportunity |
| idea | concept |
| result | outcome |
| way | method |
| place | location |
| proof | evidence |
| rules | regulations |
| freedom | liberty |
| house | residence |
| talk | discuss |
| think about | consider |
| find out | determine |
| look at | examine |
| look for | seek |
| point out | indicate |
| go ahead | proceed |
| put off | postpone |
| put up with | tolerate |
| deal with | handle |
| bring up | mention |
| set up | establish |
| go down | decrease |
| go up | increase |
| cut down | reduce |
| come back | return |
| go away | depart |
| come in | enter |
| take out | remove |
| throw away | discard |
| fill in | complete |
| find | locate |
| build | construct |
| make | create |
| speed up | accelerate |
| slow down | decelerate |
| stop | cease |
| begin | commence |
| live | reside |
| let | permit |
| allow | authorize |
| give | grant |
| take | accept |
| seem | appear |
| happen | occur |
| show | reveal |
| hide | conceal |
| change | modify |
| improve | enhance |
| make sure | ensure |
| try | attempt |
| want | desire |
| need | require |
| have to | must |
| get rid of | eliminate |
| think | believe |
| understand | comprehend |
| explain | clarify |
| ask for | request |
| say sorry | apologize |
| promise | assure |
| warn | caution |
| talk about | discuss |
| agree | consent |
| disagree | object |
| say no | decline |
| say yes | accept |
| give back | return |
| pay back | repay |
| call off | cancel |
| wait | await |
| book | reserve |
| check | inspect |
| help | support |
| tell | notify |
| show | illustrate |
| get | acquire |
| give | supply |
These word pairs are useful for understanding differences in register, but they are not always exact synonyms. The best choice depends on the meaning and context of the sentence. For example, “utilize” can sometimes replace “use,” but in many formal sentences, the simpler word “use” is still the clearer and more natural choice.