Verb grammar is an essential part in any language’s grammar and so is it important in Korean grammar. One important aspect of verb grammar are the conjugation rules. So I decided to write a bit on the essentials of Korean conjugation. Korean conjugation isn’t that hard once you connect a few dots.

Korean Verb Stem

The first important aspect to do any Korean conjugation is the Korean verb stem. The Korean verb stem is the basis for everything you will need to do to properly use the verb with the necessary verb ending. To easiest way to get the verb stem of any verb, be it an action verb or a descriptive verb (= adjective), is to use its dictionary form. The dictionary form of any Korean verb always ends in -다. Examples:

  • 요리하 : 요리하 (verb stem)
  • : 먹 (verb stem)
  • 나쁘 : 나쁘 (verb stem)

Growing Verb Stem

However, the verb stem in Korean is not fixed. They are capable to change when you add the various affixes you can use before using a verb ending. We already talked about all three possible affixes you can use: honorific affix, tense affix and the verb ending. When you add either the honorific and/or the tense affix, you will need to treat those affixes as if they are part of the verb stem for whatever you want to add after them. Examples:

  • 요리하 : 요리하 + -시- = 요리하시 (verb stem)
  • : 가 + -시- = 가시 + -었- = 가셨 (verb stem)
  • 나쁘 : 나 + 았 = 나빴 (verb stem)

Notice that the final verb’s stem, 나쁘다, changed due to the affix we were attaching. The other reason why a verb stem can change is due to it being a irregular Korean verb. The verb ending you want to attach can require the verb stem to change.

The first rule of Korean conjugation is: When you add an affix, you use the new form as the basis for adding the following part while conjugation Korean verbs.

Korean Verb Ending Patterns

In some languages you need to know a lot of rules when to conjugate a verb. Those rules are can be depended on various factors. In Korean, though, you needn’t memorize rules for all individual Korean verb endings. You see all the verb endings fall into a one of a limited amount of basic conjugation patterns. Furthermore, it becomes easier to spot which conjugation rule the verb ending falls into once you notice a few things. Let’s go over the three basics.

Korean Conjugation Group #1: 아/어

The first important group of verb endings are the verb endings that adhere to what I would call the ‘아/어 rule’. Most Korean language learners will come into contact with the ‘아/어 rule’ because some of the most basic Korean verb patterns use this pattern. Patterns such as: the present tense-아/어서, -아/어야 하다/되다 and many more.

While when written down the rules seem complicated, they are rather easy to pick up. Verb endings using this rule follow the following rules:

  1. If the verb stem contains either ㅏ or ㅗ, you attach the ending with -아 at the beginnings such as -아서.
  2. If the verb stem does not contain either of those vowels, you attach the ending with -어 at the start such as -어서.
  3. For 하다 verbs, the ending is always with 해 instead of either -아 or -어, such as 해서.

What is important to note about this type of ending in Korean conjugation, is that when there is no batchim (final consonant), the verb stem and ending fuse together. The way how it fuses depends on the vowel. Again it looks written down more complicated than it actually is. Here are the 5 rules:

  1. Stem ends in ㅏ: Drop the -아 syllable and attach the rest of the verb ending; eg. 가요.
  2. Stem ends in ㅗ: Fuse the ㅗ syllable of the verb stem and -아 syllable together and form one syllable with ㅘ as vowel; eg. 봐요.
  3. Stem ends in ㅜ: Fuse the ㅜ syllable of the verb stem and -어 syllable together and form one syllable with ㅝ as vowel; eg. 배워요.
  4. Stem ends in ㅣ:  Fuse the ㅣ syllable of the verb stem and -어 together to form one syllable with 여 as vowel; eg. 마셔요.
  5. Stem ends in any other vowel: The -어 syllable is dropped and the rest of the verb ending is attached to the verb stem; eg. 보내요.


Many Korean conjugation groups will have these calls to attention. Most Korean conjugation groups have Korean irregular verb groups they don’t play nice with their type of conjugation. In fact this conjugation group causes the most issues with Korean irregular verbs. The following Korean irregular verb groups don’t play nice and change their verb stem because of it:

Korean Conjugation Group #2: Batchim/No batchim

The second important group adhere to a rule, I call the ‘Batchim/No batchim’ rule. A batchim (받침) is the final consonant at the end of a Korean syllable. For example in the word 생일, the ㅇ is the batchim of its first syllable. For the next Korean conjugation group, the presence of a batchim or no batchim is essential.

The majority of the verb patterns that adhere to the ‘Batchim/No batchim’ rule have add ‘으’ whenever there is a batchim. Though there are a few variations on that basic principle. Furthermore there are some verb endings that adhere to the  ‘Batchim/No batchim’ rule, but have a unique form such as the Korean formal ending -ㅂ니다/습니다. We’ll go over the basic subcategories.

Add ‘으’ Subgroup

The first subcategory in the ‘Batchim/No batchim’ rule are all the verb endings that add a syllable ‘으’ whenever there is a batchim present. Common Korean verb endings that do this are -(으)면, -(으)면서, -(으)세요, -(으)러 and many others.

Also here there are few Korean irregular verb groups that act up. Those irregular verb groups are:

The ‘(으)ㄹ’  Subgroup

A second subcategory in the ‘Batchim/No batchim’ rule are the verb endings that operate with ‘(으)ㄹ’. For this subgroups the rules are very similar to the previous subgroup. However, when there is no batchim, the ㄹ becomes part of the verb stem’s final syllable. And, when there is a batchim the 으 and ㄹ create a new syllable 을. Common Korean verb endings that do this are the future tense, -(으)ㄹ까요,  -(으)ㄹ래요 and many others.

Also here there are few Korean irregular verb groups that act up. Those irregular verb groups are:

There is, though a tiny peculiarity with the ㄹ irregular verbs and this subgroup. The ㄹ batchim of these verb stems are treated as the ㄹ of the verb ending. Therefore you simply attach the rest of the verb ending during conjugation with these irregular verbs. PS: this happens also with the ending -(으)러

There is a slight deviation of this rule where the 으 becomes part of the syllable of the verb ending. This happens with verb endings who use simple ㄴ with vowels such as when you make verbs noun modifiers using -(으)ㄴ.

The Others

However, there are still some verb endings that adhere to a ‘Batchim/No batchim’, but those are not at all like the ones we have discussed so far. These are fewer in number, but the most important verb ending of this group is the -ㅂ니다/습니다. Here you simply need to know which form you have to use with a vowel and which you’ll have to use with a batchim.

Korean Conjugation Group #3: No Rule

The last group, the rest group, are the easiest to explain. Here you needn’t any rules for conjugation. For these verb endings you simply need to take the verb stem and the verb ending and attach them. You have plenty verb endings in this subgroup, verb endings such as: -고, -네요, -거나 and many more.

You can use most Korean grammar topics, if you follow the rules we’ve shared with you. Most Korean verb endings fall in one of these groups. Do you think we forgot one? Let us know in the comments.

Grammar Note: Korean Conjugation Essentials
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Grammar Note: Korean Conjugation Essentials