#korean #grammar
내다 is active but in many cases the 나다 form seems to be used more (just my subjective feeling). The relationship between them is like that of [[하다 Verb|하다 and 되다]].
The [[N이⧸가|subject particle 이/가]] and [[N을⧸를|object particle 을/를]] are optional. If they are omitted, then there is also no space between the words (at least, that is the case for 화나다/화내다 and 짜증내다/짜증나다).
# Examples
## 끝내다 and 끝나다
끝내다 (to finish) and 끝나다 (to be finished)
- N을/를 끝내다: another subject ends an object N
- 숙제를 다 끝내 [[V-아⧸어 버리다|버렸어요]]. (I have finished all my homework.)
- N이/가 끝나다: subject N ends
- 금요일에 그 수업이 끝나요. (The course ends on Friday.)
## 고장(을) 내다 and 고장(이) 나다
- 고장(을) 내다 (to break): You dropped your phone into the water and broke it.
- 고장(이) 나다 (to break down): The subject is the object that broke.
- 컴퓨터가 고장 났어요. (My computer broke down./My computer is broken.)
## 화내다 and 화나다
- 화내다/화를 내다 is to get angry and lose one’s temper in a visible way (e.g. shouting at others)
- 화나다 is getting angry (feeling) but not performing any outward action
## 짜증내다 and 짜증나다
- 짜증(을) 내다 is showing irritation
- 짜증(이) 나다 is to be annoyed/frustrated (feeling)
- 컴퓨터가 고장 날 때 짜증이 나요. (I get annoyed when my computer breaks down.)
## 사고가 나다 and 사고를 내다
- 사고가 나다: to have an accident/an accident occurs
- 사고를 내다: you caused an accident