How do you explain formal and informal language to kids?

Formal language is the careful way we talk and write when we want to sound respectful and serious, like in school assignments or when speaking to adults. Informal language is the relaxed way we talk with friends and family, often using slang, jokes, and shorter sentences.

When should my child use formal language?

Your child should use formal language in school essays, reports, and presentations, and when writing to teachers, principals, or other adults they do not know well. It is also useful in situations like job applications, interviews, and public speaking.

When is it okay to use informal language?

Informal language is usually fine in texts, chats, and conversations with friends and close family. It can also work in some creative writing or personal stories, as long as the teacher says it is appropriate for the assignment.

What is formal and informal language in writing assignments?

In writing, formal language means using complete sentences, correct grammar, and clear, polite words without slang or texting shortcuts. Informal language in writing looks more like conversation, with contractions, casual phrases, and sometimes fragments, and it is better for notes, messages, or stories told in a character’s voice.

What Is Formal and Informal Language? Definition

How to explain formal and informal language to a child

Formal language is how you talk or write when you want to sound serious and respectful, like talking to a principal or writing to a teacher. You use full sentences and avoid slang. Informal language is how you talk with friends, using shorter words, slang, and a relaxed tone. Both are useful, you just choose the one that fits the situation!

Examples of formal and informal language

Example 1 (simpler, middle grades):

Imagine a child is writing to a teacher about missing homework.

Formal language: "Dear Ms. Lee, I am sorry that I did not turn in my homework today. I forgot it at home, but I will bring it tomorrow. Thank you for understanding."

Informal language: "Hey, I forgot my homework. I’ll bring it tomorrow, ok?"

Both messages share the same idea, but the first one is more complete, polite, and careful, which fits a teacher. The second sounds like a quick text to a friend.

Example 2 (more advanced, upper grades):

Now compare how a student might start an essay about video games.

Formal language (good for an expository school essay): "Many parents are concerned about how much time children spend playing video games. However, recent studies suggest that certain games can improve problem-solving skills and teamwork."

Informal language (sounds like talking to a friend): "Lots of parents freak out about kids playing video games all the time, but some games are actually pretty good for your brain."

The formal version avoids slang like "freak out" and "pretty good," uses more precise words, and would fit a graded assignment. The informal version is fine for a conversation or a personal message, but not for a formal school essay.

Going deeper: how formal and informal language work in school

As students move through grades 4 to 10, they are asked to shift between formal and informal language depending on their purpose and audience. A science report, a history essay, or an email to a principal usually calls for formal language. A text to a friend or a quick note in a group chat is usually informal.

Formal language often uses complete sentences, more precise vocabulary, and correct grammar and conventions. Informal language may include contractions (like "don’t"), slang, emojis, and sentence fragments. Learning when to use each style helps your child sound clear and respectful in many settings.

In upper grades, students also learn that formal language is especially important in academic writing, such as expository writing, where they explain or inform. They may still use a friendly tone, but they avoid slang and keep the writing organized from the hook to the conclusion.

Common mistakes with formal and informal language

Mistake: Using very informal language (slang, texting shortcuts, or jokes) in a school essay or email to a teacher because "that’s how I really talk." Correction: School assignments and messages to adults usually need formal language, even if your child speaks more casually with friends.
Mistake: Thinking formal language must always be complicated or full of big words. Correction: Formal language should be clear, polite, and correct; simple, accurate words are often better than long, confusing ones.
Mistake: Believing informal language is "wrong" and should never be used. Correction: Informal language is appropriate and natural with friends and family; the key skill is choosing the style that fits the situation and audience.

How this shows up in everyday life

Your child already switches between formal and informal language without thinking about it. They might speak politely to a coach or librarian, then turn and use slang with friends. They may write a careful thank-you note to a relative, but send short, informal messages in a game chat. Naming these styles helps them make better choices in school and beyond.

Related terms to explore

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What is formal and informal language?