This is the 15501st most frequent Korean word.
변속기를
"변속기를" refers to a "transmission" or "gearbox" in a vehicle.
Here, '변속기를' is the object of the verb '조작하려면' (to operate), showing its role as a mechanical component requiring operation.
차에서 변속기를 부드럽게 조작하려면 기술이 필요합니다.
To smoothly operate the transmission in a car, skill is required.
In this sentence, '변속기를' functions as the object of the verb '개선하여' (to improve), indicating that the transmission underwent improvements.
현대차는 변속기를 개선하여 연비를 증가시켰습니다.
Hyundai improved the transmission to increase fuel efficiency.
The word '변속기를' is used as the object of the verb '연구했습니다' (researched), showing the main subject of investigation.