Object Particle: 를 (leul), 을 (eul)

If object has bottom consonant, 을 (eul) comes after object.

If object has no bottom consonant, 를 (leul) comes after object.

Example

I met a friend. - 나는 친구를 만났습니다.

(na neun chin goo leul man nat seum ni da)

I ate dinner with my friend. - 나는 친구와 저녁을 먹었습니다.

(na neun chin goo wa ju nyuk eul muk ut seum ni da)

Possessive Particle: 의 (eui)

Possesive Particle is like My, Your, Our, 's etc.

Example

My friend came to America. - 나의 친구가 미국에 왔습니다.

(na eui chin goo ga mi gook eh wat seum ni da)

My Brother's bag is red. - 나의 동생의 가방은 빨간색입니다.

(na eui dong saeng eui ga bang eun bbal gan saek im ni da)

Side by Side Particle : 와 (wa), 과 (gwa)

와(wa) comes if the word in front of it has no bottom consonant.

과(gwa) comes it the word in front on it has bottom consonant.

Example

Steve and I go to same school. - 스티브와 나는 같은 학교에 다닙니다

(Steve wa na neun ga teun hak gyo eh da nim ni da)

I went to baseball park with my friends.- 나는 친구들과 야구장에 갔습니다.

(na neun chin goo deul gwa ya goo jang eh gat seum ni da)