Adjusting Formality — I can adjust formality (polite vs casual) in supported contexts based on relationship and situation.

Historical Context & Motivation

Korean is one of the world's most fascinating languages when it comes to expressing social relationships through grammar. Unlike English, where politeness is mostly about word choice and tone of voice, Korean has entire speech levels (called 존댓말 for polite speech and 반말 for casual speech) built directly into verb endings. This system didn't appear overnight — it evolved over centuries, shaped by Korea's deeply Confucian social structure and hierarchical traditions.

So why should you care about formality levels? Imagine calling your teacher "dude" or texting your best friend like you're writing a business email — it would feel completely wrong. In Korean, using the wrong speech level isn't just awkward; it can come across as genuinely disrespectful. The core question this lesson addresses is: How do I know when to speak politely versus casually, and how do I actually change my sentences to match?

Core Principles of Korean Formality

Before diving into verb conjugations, it's essential to understand the social logic behind formality in Korean. The system is governed by a few fundamental principles that determine which speech level you should use in any given situation.

Visual Explanation — The Formality Spectrum

Korean has roughly seven speech levels, but in everyday life you'll mostly use two: the 해요체 (polite-informal) and the 해체 (casual). The diagram below shows where these two fit on the full formality spectrum, along with examples of who you'd talk to using each level.

As a learner, the safest strategy is to always start with 해요체 (polite-informal). It works in virtually any situation and won't offend anyone. You can think of it as your "default mode" in Korean. You only switch to 반말 when someone older explicitly says "말 놓으세요" (literally "put down your speech"), which means "feel free to speak casually." Among same-age friends, casual speech usually develops naturally once you've become close.

How It Works — Verb Ending Transformations

The magic of Korean formality lies in verb endings. The verb stem stays the same, but you swap the ending to shift the entire tone of your sentence. This is the mechanical heart of the system, and once you learn the pattern, you can transform any sentence between polite and casual forms.

The Conjugation Formula

Let's look at this with the verb 먹다 (to eat). The stem is 먹 (remove 다 from the dictionary form). The last vowel in 먹 is ㅓ, which is neither ㅏ nor ㅗ, so we use 어요 for polite and 어 for casual. Result: 먹어요 (polite) versus 먹어 (casual). The meaning is identical — only the social tone changes.

Beyond Verbs — Other Formality Markers

Formality adjustments go beyond just verb endings. You'll also encounter changes in sentence-final particles, vocabulary choices, and even how you say "yes" and "no." In polite speech, "yes" is 네 (ne), while in casual speech among friends it becomes 응 (eung). Similarly, "no" shifts from 아니요 (aniyo) to 아니 (ani). Even the word for "I" changes: 저 (jeo) in polite speech versus 나 (na) in casual speech.

Detailed Breakdown — Common Verb Conjugations

The table below shows the most common Korean verbs conjugated in both polite (해요체) and casual (해체) forms. Study the patterns carefully — you'll start to notice that the casual form is almost always just the polite form without 요.

Worked Example — Converting a Polite Dialogue to Casual

Let's walk through a realistic scenario. Imagine you've written a short dialogue in polite Korean (해요체) and now you need to convert it to casual Korean (해체) because the conversation is between two close same-age friends. The original polite dialogue is:

Polite vs. Casual — Side-by-Side Comparison

Now that you've seen how the conversion works, let's look at a comprehensive side-by-side comparison of key phrases and features across both speech levels. This table is a quick-reference guide you can come back to whenever you're unsure which form to use.

Connection to Advanced Formality — Formal Speech & Honorifics

The polite and casual levels you've learned are the foundation, but Korean's formality system goes deeper. As you advance, you'll encounter the 하십시오체 (formal-polite) level used in news broadcasts, business presentations, and military settings, as well as the honorific system (높임법) that changes not just endings but entire verb stems when talking about someone of high status.

Don't worry about mastering all seven levels right away. Even most native Korean speakers primarily use the two levels you've learned in this lesson for everyday conversation. The formal-polite level (하십시오체) will come naturally as you encounter it in Korean media, and the honorific verb system is a topic for intermediate study. For now, being able to confidently switch between 해요체 and 해체 gives you the tools to handle the vast majority of real-life Korean conversations.

Practice Problems

Lesson Summary