Nouns: Complement Marker '가/이'

01

Basic Forms

The choice between 이 (i) and 가 (gagagaka) depends entirely on the sound at the end of the preceding noun.

• If the noun ends in a consonant, add 이 (i).
• If the noun ends in a vowel, add 가 (gagagaka).

• 물 → 물이

  mul → mul·i

  water

• 학교 → 학교가

  hak·gyo → hak·gyo·gahak·gyo → hak·gyo·gahak·gyo → hak·gyo·gahak·kyo → hak·kyo·ka

  school

02

The Complement with 'To Become' and 'To Not Be'

In Korean grammar, the verbs 되다 (tœ·dadoe·datoe·datway·ta) - to become and 아니다 (a·ni·daa·ni·daa·ni·daa·ni·ta) - to not be are incomplete on their own. They require a noun to tell us what someone becomes or what something is not. This noun is marked by 이/가 (i/ga).

Even though English translates these sentences using "to be" or "a/an", Korean treats the noun as a complement that must be marked.

• 저는 선생님이 되었습니다.

  chŏ·nŭn sŏn·sæng·nim·i tœ·ŏt·ssŭm·ni·da.jeo·neun seon·saeng·nim·i doe·eot·sseum·ni·da.chŏ·nŭn sŏn·saeng·nim·i toe·ŏt·ssŭm·ni·da.ce·nun sen·sayng·nim·i tway·et·ssum·ni·ta.

  I became a teacher.

• 이것은 우유가 아닙니다.

  i·gŏ·sŭn u·yu·ga a·nim·ni·da.i·geo·seun u·yu·ga a·nim·ni·da.i·gŏ·sŭn u·yu·ga a·nim·ni·da.i·ke·sun u·yu·ka a·nim·ni·ta.

  This is not milk.

03

Using Complements with Descriptive Verbs (Adjectives)

A major difference between English and Korean is how feelings, preferences, and abilities are expressed. In English, we use transitive verbs with objects (e.g., "I like pizza"). In Korean, these concepts are often expressed using descriptive verbs (adjectives).

Because a descriptive verb describes a state rather than an action, it cannot take a direct object marker 을/를 (ŭl/rŭleul/rŭlŭl/rŭlul/rŭl). Instead, the item being described is marked with 이/가 (i/ga).

Common descriptive verbs that use this structure include:

• 좋다 (cho·tʰajo·tacho·t'aco·tha) - to be good
• 싫다 (sil·tʰasil·tasil·t'asil·tha) - to be dislikable/bad
• 필요하다 (pʰi·ryo·ha·dapi·ryo·ha·dap'i·ryo·ha·daphi·lyo·ha·ta) - to be necessary
• 무섭다 (mu·sŏp·ttamu·seop·ddamu·sŏp·ttamu·sep·tta) - to be scary

• 시간이 필요해요.

  si·gan·i pʰi·ryo·hæ·yo.si·gan·i pi·ryo·hae·yo.si·gan·i p'i·ryo·hae·yo.si·kan·i phi·lyo·hay·yo.

  Time is necessary. (I need time.)

• 뱀이 무서워요.

  pæm·i mu·sŏ·wŏ·yo.baem·i mu·seo·wŏ·yo.paem·i mu·sŏ·wŏ·yo.paym·i mu·se·wŏ·yo.

  Snakes are scary. (I am afraid of snakes.)

04

The Double Subject Construction

You will often see sentences that appear to have two subjects. This structure is used to clarify who is experiencing the feeling or state.

• The Topic (marked with 은/는 (ŭn/nŭneun/nŭnŭn/nŭnun/nŭn)) indicates the person experiencing the state.
• The Complement/Subject (marked with 이/가 (i/ga)) indicates the specific thing that the state describes.

Structure: [Experiencer 은/는] + [Target 이/가] + [Descriptive Verb]

Literally, the sentence 나는 고양이가 좋아 (na·nŭn ko·yang·i·ga cho·ana·neun go·yang·i·ga jo·ana·nŭn ko·yang·i·ga cho·ana·nun ko·yang·i·ka co·a) translates to "As for me, cats are good." However, the natural translation is "I like cats."

• 저는 사과가 좋아요.

  chŏ·nŭn sa·gwa·ga cho·a·yo.jeo·neun sa·gwa·ga jo·a·yo.chŏ·nŭn sa·gwa·ga cho·a·yo.ce·nun sa·kwa·ka co·a·yo.

  I like apples.

• 동생은 개가 싫어요.

  tong·sæng·ŭn kæ·ga si·rŏ·yo.dong·saeng·eun gae·ga si·reo·yo.tong·saeng·ŭn kae·ga si·rŏ·yo.tong·sayng·un kay·ka si·le·yo.

  My younger sibling dislikes dogs.

05

Comparison: Descriptive vs. Action Verbs

It is vital to distinguish between descriptive verbs (adjectives) and action verbs, as this dictates which particle you must use.

1. Descriptive Verb: 좋다 (cho·tʰa) - to be good

Uses 이/가 (i/ga). Focuses on the nature of the object.

• 날씨가 좋아요.

  nal·ssi·ga cho·a·yo.nal·ssi·ga jo·a·yo.nal·ssi·ga cho·a·yo.nal·ssi·ka co·a·yo.

  The weather is good.

2. Action Verb: 좋아하다 (cho·a·ha·da) - to like

Uses 을/를 (ŭl/rŭleul/rŭlŭl/rŭlul/rŭl) - Object Marker. Focuses on the action of the person.

• 저는 날씨를 좋아해요.

  chŏ·nŭn nal·ssi·rŭl cho·a·hæ·yo.jeo·neun nal·ssi·reul jo·a·hae·yo.chŏ·nŭn nal·ssi·rŭl cho·a·hae·yo.ce·nun nal·ssi·lul co·a·hay·yo.

  I like the weather.

Both sentences convey a positive feeling about the weather, but the grammatical structure is different. If you use 좋다 (cho·tʰajo·tacho·t'aco·tha), you must use 이/가 (i/ga). If you use 좋아하다 (cho·a·ha·dajo·a·ha·dacho·a·ha·daco·a·ha·ta), you must use 을/를 (ŭl/rŭleul/rŭlŭl/rŭlul/rŭl).