Korean Past Tense: Master Korean Verb Conjugation the Right Way

You're watching a Korean show and someone says "먹었어요" (meogeosseoyo). You know 먹다 (meokda) means "to eat," but what's all that extra stuff at the end?

Welcome to Korean past tense conjugation. It looks scary at first—all those vowel rules and irregular verbs. But here's the thing: Korean verb conjugation is way more systematic than English past tense. Once you get the pattern, you can conjugate verbs in past tense without thinking twice.

Let me break down Korean grammar the way I wish someone had explained it to me when I started to learn Korean.

How to Form the Past Tense in Korean (The Core System)

Korean past tense works on vowel harmony. Bright vowels get one verb ending, dark vowels get another. That's it. That's the whole system for Korean conjugation.

If the verb stem ends in ㅏ or ㅗ → add -았어요

If the verb stem ends in anything else → add -었어요

If the verb ends in 하다 → change it to 했어요

That's the basic pattern for Korean verb conjugation. No memorizing dozens of irregular past tense forms like English makes you do (go/went, eat/ate, drink/drank...). Korean just slaps a past tense ending on there and calls it a day.

This same rule works for Korean adjectives too. Yep, adjectives conjugate like verbs in Korean—which is weird if English is your first language, but it's actually an important aspect of Korean grammar that makes the tense system more consistent.

Korean Verb Endings: Understanding Vowel Contractions

Here's where people get confused when they learn how to conjugate verbs in past tense. When you add -았어요 or -었어요 to a stem that ends in a vowel, the vowels smash together.

Examples:

This isn't some random thing—it happens because saying "자았어요" feels awkward. Korean speakers naturally contracted it over time, and now that's just how Korean verb conjugation works.

You don't need to memorize every contraction. Once you start hearing these verbs in actual Korean content—shows, videos, conversations—the contracted forms of Korean verbs just sound right. Your brain picks up the pattern without forcing it.

Past Tense in Korean: Irregular Verbs That Break the Rules

Look, I'm not going to lie to you. There are a few irregular verbs that break the Korean conjugation rules. But "irregular" in Korean means way less chaos than English irregular verbs.

ㄷ irregular verbs:

The ㄷ becomes ㄹ before -었어요. Why? Because 걷었어요 sounds clunky. That's literally the reason. When you use the past tense with ㄷ irregular verbs, this pattern repeats.

ㅂ irregular verbs:

The ㅂ drops and 우 sneaks in. Again, it's about making the past tense form flow better when you say it out loud.

ㅡ irregular verbs:

When the stem ends in a vowel like ㅡ, that vowel disappears, and you look at what came before it to decide between -았어요 and -었어요.

Is this annoying to memorize? Sure. But compared to English past tense, where "go" becomes "went" for absolutely no logical reason, Korean's irregular verbs are pretty reasonable. They follow pronunciation logic, not arbitrary historical accidents.

Korean Past Tense vs English Past Tense: What Nobody Tells You

Here's something that confused the hell out of me when I started learning Korean: Korean past tense doesn't always mean the same thing as English past tense.

In English, "He was my friend" usually implies you're not friends anymore. In Korean grammar, 친구였어요 (chinguyeoseoyo) just describes a state in the past. It doesn't necessarily suggest the friendship ended. The Korean past tense often works differently from what English speakers expect.

Also, Koreans sometimes use past tense to describe present situations that resulted from actions that happened in the past. If someone says 입었어요 (ibeosseoyo, literally "wore"), they might mean "I'm wearing it right now" because the action of putting it on is complete.

This semantic difference matters when you're trying to understand real Korean language content. Sometimes what sounds like past tense is describing right now. Understanding this aspect of Korean verb usage helps you interpret Korean shows and conversations more accurately.

Conjugate Korean Verbs in Different Tenses and Formality Levels

The Korean language has a formality system built into verb conjugation, and the past tense is no exception. The -었어요/-았어요 endings I've been showing you? That's polite informal speech.

Casual speech (with friends):

Formal polite speech:

Honorific past tense (for respected people):

If you're also working on Korean present tense or future tense, you'll notice the same formality patterns apply. The tense conjugation system in Korean grammar stays consistent across present, past, and future tense forms.

Understanding the Korean conjugation system for both present tense and past tense helps you see how Korean verbs and adjectives work together. Our Korean verbs conjugation guide covers more about how Korean verb endings work across different tenses.

The Korean Verb 이다 (to be) in Past Tense

The verb 이다 (to be) conjugates slightly differently. After a consonant, you use 이었어요 (ieosseoyo), which often contracts to 였어요 (yeosseoyo). After a vowel, you use 였어요 (yeosseoyo) directly.

Examples:

This is one of those Korean grammar rules where the proper conjugation depends on whether the word before 이다 ends in a consonant or vowel. The dictionary form 이다 transforms based on context.

Korean Past Tense Conjugation: The Continuous Tense

Want to say "I was eating"? That's past continuous tense in Korean. You add -고 있었어요 to the verb stem:

The continuous tense works the same for every single verb. You don't even need to consider the last vowel because you're always adding -고. It's actually easier than the simple past for beginners.

This is a bit of a cheat if you're not sure of the correct past tense ending for irregular verbs. Just use the past continuous form and you'll be understood, even if it's not perfectly natural in every context.

How to Use the Past Tense in Korean: Learning from Real Content

Reading Korean grammar rules is fine, but you won't master Korean verb conjugation until you see verbs in past tense used thousands of times in real contexts. That's just how language learning works.

The problem with textbooks and traditional Korean language courses is that they give you made-up practice sentences like "저는 어제 사과를 먹었어요" (I ate an apple yesterday). Sure, grammatically correct for learning Korean grammar. Also completely useless for understanding how Koreans actually conjugate verbs in conversation.

Real Korean—the stuff in shows, YouTube videos, casual conversation—uses past tense differently. People jump between present tense and past tense mid-story. They use the past continuous (먹고 있었어요) way more than grammar books suggest. They mix formal and informal verb endings based on social context.

You need exposure to all of that, not just Korean grammar drills. This is where learning Korean from actual content makes a massive difference. When you watch Korean shows and someone says "어제 뭐 했어?" (What did you do yesterday?), you're not just seeing Korean past tense conjugation in action—you're hearing the natural rhythm, the casual speech level, the context that makes Korean verb usage click.

If you're still wrapping your head around the basics, check out our Korean grammar overview first. It covers the foundational Korean grammar concepts that make past tense conjugation easier to understand.

Korean Conjugation Practice That Actually Works

Want to know what doesn't work for learning Korean verb conjugation? Filling out grammar worksheets. Seriously, you can conjugate verbs on paper all day and still freeze up when trying to use past tense in Korean conversation.

What does work for Korean language learning:

The last one is huge. Talking about your day forces you to conjugate verbs constantly: "I woke up, I ate breakfast, I went to work..." You'll stumble at first with the proper conjugation of Korean verbs, but that's how you build the muscle memory to use the past tense naturally.

If you're using Anki to learn Korean, make sure you're learning from good Korean Anki decks that include real sentences with verbs and adjectives in context, not just isolated vocabulary. Context is everything for understanding how to conjugate Korean verbs across different tenses.

Past and Present Tense: Building Your Korean Verb Mastery

Once you've got past tense down, Korean present tense and future tense follow similar patterns. The verb stem stays the same—you just swap the endings. That's what makes Korean conjugation more systematic than English.

Present tense verbs:

Future tense:

The vowel harmony rules for Korean past tense (ㅏ/ㅗ vs other vowels) apply to present tense too. If you understand past tense conjugation, you've already learned the core system for all Korean verb endings.

The more you practice Korean conjugation across different tenses, the faster your brain recognizes the patterns. You stop thinking "okay, this stem ends in ㅗ, so I use -았어요" and just automatically know the right tense form.

Anyway, if you want to actually use Korean past tense with real Korean content, that's exactly what Migaku was built for. You can watch Korean shows and YouTube videos with the browser extension, and when you hear a verb in past tense you don't recognize, just click it. Instant lookup, instant flashcard creation with the full sentence context showing how to form the past tense naturally.

The mobile app lets you review those Korean verb conjugation examples using spaced repetition, so you're not just memorizing 먹었어요 in isolation—you're remembering it from the actual scene where someone used it. That's how you internalize when to use the past tense and which speech level fits the situation.

Plus, the more you immerse yourself in real Korean language content, the faster those irregular verbs and vowel contractions just start sounding right. Your brain picks up Korean grammar patterns from thousands of examples way better than from textbook rules about how to conjugate a verb or adjective.

There's a 10-day free trial if you want to check it out. No credit card needed, just actual Korean content you can learn Korean from while building your understanding of Korean verb conjugation, Korean past tense, and all the other grammar you need to actually speak the language.