This phrase has two parts. The first part is ~게 되면, and the second part is ~게 돼요.
The meaning of "~게 되면" is equivalent to "when(ever) or if," and that of "~게 돼요" is equivalent to "am made/compelled to" or "habitually(usually)."
For example,
- 음식점에 가게 되면, 비빔밥을 주문하게 돼요 = When(ever) I go to a restaurant, I am made/compelled to order a bibimbap. (I habitually/usually order a bibimbap.)
음식점 = a restaurant
가다 = go
가게 되면 = When(if) I go
비빔밥 = a Korean dish (The dish consists of rice with various kinds of vegetables, beef(usually mince), fried egg, Korean red chili paste and sesame oil.)
주문 = order (n.)
주문하다 = order (v.)
주문하게 돼요 = I habitually order
Note: The plain form of 되면 and 돼요 is '되다' which means 'to become.' Therefore, the literal translation of the sentence above is:
- 음식점에 가게 되면, 비빔밥을 주문하게 돼요 = When(ever) it becomes that I go to a restaurant, it becomes that I order bibimbap
Also, in the first part when a noun is used instead of a verb, 이/가 되면 is used instead.
For example,
- 아침이 되면, 신문을 보게 된다 = When it is morning, I habitually(usually) read a newspaper
The literal translation of the sentence above is, "When it 'becomes' morning, I 'become' reading a newspaper."
The sentence doesn't make sense grammatically in English but I hope the literal translation will help you get the nuance of the phrase.
Conjugation rule
Take 다 off a plain form of verbs and attach 게 되면/게 돼요 to it.
하다(do) → 하게 되면 = When(ever) I do
하다(do) → 하게 돼요 = I habitually/usually do (or I am made/compelled to do)
- 하게 돼요 = I habitually do
- 가게 돼요 = I habitually go
- 오게 돼요 = I habitually come
- 먹게 돼요 = I habitually eat
- 자게 돼요 = I habitually sleep
- 말하게 돼요 = I habitually speak
- 듣게 돼요 = I habitually listen
- 보게 돼요 = I habitually watch
Example Sentences
- 늦은 밤이 되면, 아이스크림을 먹게 돼요 = When(ever) it is late at night, I habitually eat an icecream
- 정오가 되면 졸려서 낮잠을 자게 돼요 = When(ever) it is noon, because I'm tired(sleepy), I habitually have a nap (Lit. sleep a nap).
- 컴퓨터만 키게 되면, 음악을 듣게 돼요 = When(ever) I turn on the computer, I habitually listen to music.
- 시내만 나가게 되면, 영화를 보게 돼요 = When(ever) I go to town, I habitually go to movies (Lit. watch movies).
- 운동만 하게 되면, 물을 많이 마시게 돼요 = When(ever) I exercise, I habitually drink a lot of water.
Usually
As a side note, when you would like express something that you
"usually" do and not what you are "made/compelled to" do,
"주로" is often used.
For example,
- 음식점에 가면, "주로" 비빔밥을 주문해요 = When I go to a restaurant, I usually order a bibimbap. (There is no nuance of being "made/compelled to" order a bibimbap.)
- 운동하고 나서는 "주로" 물을 많이 마셔요 = After exercise, I usually drink a lot of water. (Some people may not drink a lot of water and other people may not drink water at all but as for me, I "usually"(whether "I'm made/compelled to" or not, we do not know) drink a lot of water.)
- 시내에 나가면 주로 영화를 봐요 = When I go to town, I usually go to movies. (Lit. watch movies)
- 학교에는 주로 걸어가요 = I usually walk to school.
- 회사에는 주로 차로 가요 = I usually go to work by car.
