In a sentence, the grammatical function of words depend on
쳤어요 (Cheolsu hit the ball).
쳤어요( The ball hit Cheolsu).
Postpositions `가/이' come
after nouns, pronouns, and numerals to make the subject form.
after nouns, pronouns, and numerals to make the object form.
Other postpositions consist of `에'
which signifies `direction' or `destination,'
`에서' which signifies `location,' and `로/으로'
which signifies `the means' or a `tool.'
서울에 가요. (I'm going to
학교에서 공부해요. (I study at
택시로 가요. (I'm going by