Unformal or Informal? Learn the Correct Usage with Examples

If you’re unsure whether unformal or informal is correct, the short answer is that informal is the standard and widely accepted English word.

While unformal occasionally appears in older texts or informal discussions, it is considered nonstandard and is rarely used by native speakers today.

This confusion often happens because many English adjectives form opposites by adding the prefix un-.

In this guide, you’ll learn the difference between unformal and informal, why one is preferred, when to use informal, and how to avoid this common vocabulary mistake.

Quick Answer

Word	Correct?	Meaning
Informal	✅ Yes	Casual, relaxed, or not following formal rules.
Unformal	❌ Nonstandard	Rarely used and generally avoided in modern English.

Use informal in almost every situation. It is the word recognized by dictionaries and style guides.

Why Do People Search “Unformal or Informal”?

Many English words create opposites with the prefix un-, such as:

unfair
unhappy
unclear
unsafe

Because of this pattern, it’s natural to assume that the opposite of formal should be unformal.

However, English doesn’t always follow predictable rules. In this case, the accepted opposite of formal is informal, not unformal.

What Does “Informal” Mean?

Informal describes something that is relaxed, casual, or not official.

It can refer to:

everyday conversations
casual clothing
friendly emails
relaxed meetings
nonofficial situations
conversational writing

Examples

We had an informal meeting before the presentation.
Her email was friendly and informal.
The event has an informal dress code.
They spoke in an informal tone.

Is “Unformal” a Real Word?

Technically, unformal has appeared in some historical writings, but it is not considered standard English today.

Major dictionaries such as the Oxford English Dictionary, Merriam-Webster, Cambridge Dictionary, and Collins Dictionary recognize informal as the standard opposite of formal. They do not recommend using unformal in modern writing.

For professional, academic, and everyday communication, always choose informal.

Unformal vs Informal

Feature	Informal	Unformal
Standard English	✅ Yes	❌ No
Found in modern dictionaries	✅ Yes	Rare or not recommended
Used by native speakers	✅ Very common	❌ Very uncommon
Appropriate in business writing	✅ Yes	❌ No
Appropriate in academic writing	✅ Yes	❌ No

Why English Uses “Informal” Instead of “Unformal”

The prefix in- often means “not” before certain adjectives.

Examples include:

inaccurate
incomplete
inactive
informal

These words became established through the historical development of English and Latin influences. As a result, informal became the accepted opposite of formal, while unformal never entered widespread standard usage.

When to Use “Informal”

Use informal whenever you’re describing communication or situations that are casual rather than official.

Everyday Conversation

We kept the discussion informal.

Workplace

Friday meetings are usually informal.

Email

An informal email is appropriate for close coworkers.

Education

Students often write in an informal style when messaging classmates but should use a formal style in assignments.

Social Media

Most social media posts use an informal tone.

Formal vs Informal

Understanding the difference between formal and informal helps you choose the right writing style.

Formal	Informal
Professional	Casual
Official	Friendly
Structured	Relaxed
Used in reports	Used in conversations
Used in academic writing	Used in everyday communication

Common Mistakes

Avoid these mistakes:

❌ unformal meeting
❌ unformal email
❌ unformal language
❌ unformal conversation

Use these instead:

✅ informal meeting
✅ informal email
✅ informal language
✅ informal conversation

Easy Memory Trick

Remember this simple rule:

If you mean “not formal,” think “informal,” not “unformal.”

Another easy trick is to remember that dictionaries, schools, and professional writers consistently use informal.

Common Phrases with “Informal”

You’ll often see informal in these expressions:

informal language
informal writing
informal meeting
informal conversation
informal email
informal interview
informal education
informal greeting
informal tone
informal communication

These are all standard and widely accepted in modern English.

Is the Word Different in British and American English?

No.

Both British English and American English use informal as the correct word. There is no regional preference for unformal.

FAQs

Is unformal a correct English word?

It exists in rare historical usage, but it is considered nonstandard. Informal is the correct choice.

Which is correct: unformal or informal?

Informal is the accepted and recommended word.

Why isn’t unformal commonly used?

English adopted informal as the standard opposite of formal, and it became the accepted form in modern usage.

Can I use unformal in academic writing?

No. Use informal instead.

Is informal appropriate in professional writing?

Yes, when you’re describing a casual tone or situation.

Is informal the opposite of formal?

Yes. Informal is the standard antonym of formal.

Do dictionaries recognize unformal?

Major modern dictionaries recognize informal as the standard term and generally do not recommend unformal.

Is informal used in both American and British English?

Yes. Both varieties of English use informal.

Final Thoughts

When deciding between unformal or informal, the correct choice is almost always informal. Although unformal may occasionally appear in older or uncommon sources, it is not part of standard modern English and should be avoided in everyday, academic, and professional writing.

By choosing informal, you’ll follow accepted grammar, match dictionary usage, and communicate more naturally with English speakers.

Whenever you want to describe something casual, relaxed, or unofficial, informal is the word you can use with confidence.