연구하다 (yeon-gu-ha-da, yeonguhada) · 연구되다 (yeon-gu-doe-da, yeongudoeda)
'연구하다' (yeonguhada) is used when the subject actively conducts research, while '연구되다' (yeongudoeda) is used when something is passively researched.
One lane per word — no nested boxes, just the gist.
To actively investigate or analyze a subject or phenomenon
When to use
active research, researcher role, subjective investigation
The nuance
Used when the subject actively performs the research; it has an active meaning.
To be researched or studied by others; to be the object of research
When to use
passive research object, researched entity, objective research target
The nuance
Used when the subject is passively the object of research; it has a passive meaning.
그 교수님은 암 치료법을 연구한다.
geu gyo-su-nim-eun am chi-ryo-beop-eul yeon-gu-han-da., geu gyo su nim eun am chi ryo beop eul yeon gu han da.
The professor actively conducts research, so '연구하다' is correct.
그 암 치료법은 여러 대학에서 연구된다.
geu am chi-ryo-beop-eun yeo-reo dae-hak-e-seo yeon-gu-doen-da., geu am chi ryo beop eun yeo reo dae hak e seo yeon gu doen da.
The treatment is the object of research, so '연구되다' is appropriate.
연구되다 교수님은 최신 기술을 사용한다.
yeon-gu-doe-da gyo-su-nim-eun choe-sin gi-sul-eul sa-yong-han-da., yeon gu doe da gyo su nim eun choe sin gi sul eul sa yong han da.
'연구되다' is for the object, not the subject; incorrect for describing a researcher.
학생들이 새로운 이론을 연구한다.
hak-saeng-deul-i sae-ro-un i-ron-eul yeon-gu-han-da., hak saeng deul i sae ro un i ron eul yeon gu han da.
Students actively research, so '연구하다' is correct.
새로운 이론은 학생들에 의해 연구된다.
sae-ro-un i-ron-eun hak-saeng-deul-e ui-hae yeon-gu-doen-da., sae ro un i ron eun hak saeng deul e ui hae yeon gu doen da.
The theory is the object of research, so passive '연구되다' fits.
나는 연구되다 논문을 발표했다.
na-neun yeon-gu-doe-da non-mun-eul bal-pyo-haess-da., na neun yeon gu doe da non mun eul bal pyo haess da.
The subject is not an object of research here; '연구되다' is inappropriate.
그 회사는 신제품 개발을 연구한다.
geu hoe-sa-neun sin-je-pum gae-bal-eul yeon-gu-han-da., geu hoe sa neun sin je pum gae bal eul yeon gu han da.
The company actively researches, so '연구하다' is correct.
신제품 개발은 그 회사에서 연구된다.
sin-je-pum gae-bal-eun geu hoe-sa-e-seo yeon-gu-doen-da., sin je pum gae bal eun geu hoe sa e seo yeon gu doen da.
New product development is the object of research, so '연구되다' fits.
Which word is used when someone actively conducts research?
Which word is used when the research object is passively studied?
Which is incorrect? "That paper is researched by students."
