이/가 This particle is added to the end of a subject to designate it as the subject of the sentence. For words that finish with a vowel, 가 is added, and for words that end with a consonant, 이 is added. For example: – 민희씨가 빵을 먹어요 [Minhee-ssi-ga bbang-eul mu-kuh-yo]. (Minhee is eating bread.). 민희씨 ends with a vowel (ㅣ), therefore ‘가’ is added after the subject 민희 (Minhee). Another example of using the particle ‘이’ is 과일이 비싸요 [Gwa-il-i bi-ssa-yo]. (The fruit is expensive.). The subject 과일 finishes with a consonant (ㄹ), therefore ‘가’ is added after the subject. Another usage for the particle이/가 is when the subject functions to emphasize the preceding subject. For example: – 내가 했어요! [nae-ga hat-uh-yo]. (I did it!). The final usage for particle 이/가is to express new information or the topic of a sentence. For example, 동생이 지금 자요 [Dong-saeng-I ji-gum ja-yo]. (My younger brother/sister is sleeping now.)

This should be set up as the number 1 question in a forum FAQ. There's at least one like that every week