This is the 4762nd most frequent Korean word.
고래를
"고래를" means "whale" (accusative form in a sentence).
In this sentence, '고래를' refers to 'whale' as the direct object of the verb '보았다' which means 'saw'.
나는 바다에서 고래를 보았다.
I saw a whale in the ocean.
In this sentence, '고래를' refers to 'whale' as the direct object of the verb '찾고 있다' which means 'searching for'.
아이들은 그림책에서 고래를 찾고 있다.
Children are searching for the whale in the picture book.
In this sentence, '고래를' is used as the direct object of the verb '연구하고 있다', indicating that whales are the subject of the research.