General Rules of Verb Conjugation in Korean

→ Action verbs and Descriptive verbs

In English, words are like “pretty,” “big,” and “important” are categorized as adjectives, whereas words like “to add,” “to jump,” “to study” are categorized as verbs. However, most Korean equivalents of English adjectives are originally in the infinitive form and are treated like verbs, therefore they must be conjugated to be used in the “modifier” format, which works similarly to English adjectives.

For example, “비싸다” is a descriptive verb (adjective in the infinitive form) that would translate to “to be expensive.” To use it as an adjective, you need to conjugate it to the adjective form, 비싼 (present tense), 비쌀 (future tense), or 비쌌던 (past tense). In English, this kind of difference is expressed through tense change of the “be” verb, but in Korean, the conjugation of the verb itself can contain the role of the “be” verb.

Examples 크다 = to be big (descriptive verb) 큰 = big (base adjective form)

크다 = to grow (action verb)
큰 = that which has grown; grew (past tense adjective form)

→ Formality Levels

In Korean, there are several levels of formality. Formality levels on the more “formal” side are generally called 존댓말, and the rest are called 반말. 존대 means “to treat with respect,” while 반 means “half.” Although you cannot “half” speak to someone, 반말 is used with someone who you are certain is younger than you or is the same age. 존댓말 is used with everyone else. It is not appropriate to use 반말 without the other person’s consent; therefore, if you are not sure which formality level to use, it is best to start off using 존 댓말.

There are two main (among many) types of 존댓말 endings: -(아/어/여)요 and -(스)ᄇ니다 (e.g. 가요, 갑니다). The -(아/어/여) 요 form is the more commonly used ending for 존댓말, whereas (스)ᄇ니다 is generally used in more formal settings. If you put -아, -어, or -여 at the end of a verb stem (without -요), it becomes 반말.

If a verb’s dictionary form (infinitive) is 먹다, the 반말 form is 먹어, and the 존댓말 forms are 먹어요, 먹습니다, etc.

→ Dictionary Form (Infinitive)

Every verb in Korean ends with -다. In most cases, before you conjugate the verb into different tenses and voices, you drop the -다 from the end of the verb and you are left with the verb stem. With the verb stem, you then conjugate the verb. When you apply a conjugation rule to a verb, be sure to remove the -다. For example, if the verb is 잡다 in the infinitive, remove the -다, and the remaining verb stem is 잡. From there, you can add various endings.

→ -아, -어, or –여

For many Korean verb conjugations, the verb stem is followed by -아, -어, or -여. If the sentence is in 반말, the verb will end there to make a present tense statement. If the sentence is in 존댓말, you need to add -요 at the end in addition to 아, -어, or –여. To determine which of these endings to use with a verb stem, simply look at the last syllable of the verb stem: if it ends with the vowel ᅩ or ᅡ, you add -아; if it ends with any other vowel, you add -어; and when verb stem’s last syllable is 하, you add -여. When - 하 and -여 are combined, it becomes 해. You will see these suffixes often in many conjugations, and these suffixes can also be followed by other sentence endings.

→ Present Tense = -아/어/여요

The present tense in Korean covers a wider range of tenses than in English. Therefore, a sentence in the present tense in Korean, e.g. “가요,” can be translated to “I go,” “I’m going,” “I’m going to go,” or even “I will go.”

To construct a present tense sentence in Korean, add -아요, -어요, or -여요 after the verb stem. You can simply drop -요 at the end to change this to 반말.

Examples 예쁘다 = to be pretty 예뻐요 = It is pretty. (존댓말) 예뻐 = It is pretty. (반말) 일하다 = to work 일해요 = I work.; I am working.; I am going to work. (존댓말) 일해 = I work.; Get to work. (반말)

→ Past Tense = -았/었/였어요

Add -았어요, -었어요, or -였어요 after the verb stem to form a past tense statement. In most cases, it suffices to use -았어 요, -었어요, or -였어요, but in some cases, there is an extra -었 added between -았/었/였 and -어요 to form -았었어요, -었었어 요, or -였었 어요. This refers to an event that happened long ago or earlier than another past event. There are many variations of the past tense, but just remember that the suffixes -았/었/ 였 are almost always used to end a sentence in the past tense.

→ Future Tense = -(으)ᄅ 거예요

-(으)ᄅ in itself has a meaning related to the future, and by saying “-(으)ᄅ 거예요,” you are literally saying “It’s that I will....” If the verb stem ends with a consonant at the end of the last syllable, you add -을 거예요. If the verb stem ends with a vowel, add -ᄅ 거예요. This is different from the future tense, (으)ᄅ게요, in the sense that when you say -(으) ᄅ게요, you are expecting a response (approval or reaction) from the other person, whereas when you say -(으)ᄅ 거예요, you are simply stating what your plans are. Although -(으) ᄅ 거예요 is a future tense sentence ending, you can also use this to express your assumption about something. Depending on the context, -(으)ᄅ 거예요 can be translated as either “it will/I will/they are going to” or “I think/I assume.”

Examples 있다 = to exist, to have 시간이 있다 = to have time

시간이 있을 거예요 = There will be time.; I think they have time. 

→ Present Progressive = -고 있어요

있어요 means “to be” whereas -고 있어요 refers to a certain state that the subject is in or an action that the subject is do- ing. By adding -고 있어요 to the verb stem, you can express the meaning of “to be doing something.” Even though the present tense covers a wider range of tenses in Korean, -고 있어요 is sometimes used to emphasize the fact that you are doing something “right at this moment.” If you want to use this end- ing in 반말, you can simply drop -요 from the end.

Examples 자다 = to sleep
자요 = She sleeps.; She is sleeping.

자고 있어요 = She is sleeping.; She is in the middle of sleeping. 

→ Present Status = -아/어/여 있 어요

-아/어/여 있어요 can be considered similar to -고 있어요, but the usage is very different. When you use a verb stem and add -아/어/여 있어요 after, it means the subject is in a state where they are still doing that action. This can not be used with just any verb, but rather with verbs that can describe a static state related to the verb. Common examples are 서다 (to stand), 앉 다 (to sit), and 눕다 (to lie down). You can conjugate these to “서 있어요” to mean “they are standing,” “앉아 있어요” to mean “they are sitting,” and “누워 있다” to mean “they are lying (on the bed or floor).” In addition, -아/어/여 있어요 can be used with verbs in passive voice to describe how an action has been done “to” something and how that “something” re- mains in a static state. An example is “깨져 있다,” which is 깨지 다 + -아/ 어/여 있다, and has the meaning of “to be in a broken state” as opposed to “to get broken.”