Allowed to - 해도 된다

Allowed to - 해도 된다 

Informal Form

Informal	are allowed to	were allowed to
Written	해도 된다	해도 됐었다
Spoken	해도 돼	해도 됐었어

Informal	aren't allowed to	weren't allowed to
Written	하면 안된다	하면 안됐었다
Spoken	하면 안돼	하면 안됐었어

Note:

해도 돼 means "allowed to do" and 안해도 돼 means "don't have to do," NOT "not allowed to do." This needs some explanations.

First of all, 돼 means "ok or allowed." 해도 돼 literally means "doing is ok." 안해도 literally means "not doing" therefore 안해도 돼 literally means "not doing is ok" which means "don't have to do."

하면 안돼 means "not allowed to do." 하면 literally means "if I do" and 안돼 means "not ok" therefore 하면 안돼 literally means "if I do it, it's not ok" which can be expressed as "not allowed to do"

Compare this with Have to - 해야 한다

However, you don't have to know these explanations to use them. Actually, I've never thought about why these mean what they mean until today. The best way to learn them is to use them frequently until they become memorised.

Rules 

1. Attach 도 된다/도 됐었다/도 돼/도 됐었어 to the positive informal spoken form of verbs Verbs - Present, Past 

• 해 → 해도 된다 = allowed to do
  
• 가 → 가도 된다 = allowed to go
  
• 봐 → 봐도 된다 = allowed to see
  
• 들어 → 들어도 된다 = allowed to hear
• 먹어 → 먹어도 된다 = allowed to eat
  
• 마셔 → 마셔도 된다 = allowed to drink
• 달려 → 달려도 된다 = allowed to run
  
• 앉아 → 앉아도 된다 = allowed to sit
  
• 놀아 → 놀아도 된다 = allowed to play/muck around

2a. Take 다 off a plain form of verbs without a final consonant and attach 면 안된다/면 안됐었다/면 안돼/면 안됐었어 to it. (Includes verbs with ㄹ as a final consonant)

• 하다 → 하면 안된다 = aren't allowed to do
  
• 가다 → 가면 안된다 = aren't allowed to go
• 춤추다 → 춤추면 안된다 = aren't allowed to dance
  
• 놀다 → 놀면 안된다 = aren't allowed to play/muck around
  
• 밀다 → 밀면 안된다 = aren't allowed to push
  
• 돌다 → 돌면 안된다 = aren't allowed to spin

2b. Take 다 off a plain form of verbs with a final consonant and attach 으면 안된다/으면 안됐었다/으면 안돼/으면 안됐었어 to it.

• 먹다 → 먹으면 안된다 = aren't allowed to eat
  
• 앉다 → 앉으면 안된다 = aren't allowed to sit
  
• 숨다 → 숨으면 안된다 = aren't allowed to hide
  
• 잡다 → 잡으면 안된다 = aren't allowed to catch
  
• 집다 → 집으면 안된다 = aren't allowed to pick up
  
• 접다 → 접으면 안된다 = aren't allowed to fold

Exceptions

• 듣다 → 들으면 안된다 = aren't allowed to listen
• 걷다 → 걸으면 안된다 = aren't allowed to walk
  

Example sentences
Written form

• 부페에서는 먹고 싶은 만큼 먹어도 된다 = At a buffet (restaurant), people are allowed to eat as much as they want.
• 시험을 마친 사람은 집에 가도 된다 = Those who have finished the exam can go home.
  
• 도서관에서는 크게 얘기하면 안된다. = It is not allowed to speak loudly in the library.
  
• 신생아들은 딱딱한 음식을 먹으면 안된다. = Infants are not allowed to eat solid food.
• 작년까지 학생들은 매점 자판기를 사용해도 됐었다 = Until last year, students were allowed to use a stall vending machine.

Spoken form

• TV 봐도 돼 = You are allowed to watch TV. (You can watch TV.)
• 이 케잌 먹어도 돼 = You are allowed to eat this cake. (You can eat this cake,)
• 술과 담배는 사면 안돼 = You are not allowed to buy alcohol and tobacco.
• 어제까지 놀아도 됐었어 = Until yesterday, I was allowed to muck around.
• 작년까지 빅토리아공원에는 들어가면 안됐었어 = Until last year, people were not allowed to enter the Victoria park.
  

Formal Form

Formal	are allowed to	were allowed to
Written	해도 됩니다	해도 됐었습니다
Spoken	해도 돼요	해도 됐었어요

Formal	aren't allowed to	weren't allowed to
Written	하면 안됩니다	하면 안됐었습니다
Spoken	하면 안돼요	하면 안됐었어요

Note: The rules are the same as above.

Example sentences
Written form

• 부페에서는 먹고 싶은 만큼 먹어도 됩니다 = At a buffet (restaurant), people are allowed to eat as much as they want.
• 시험을 마친 사람은 집에 가도 됩니다 = Those who have finished the exam can go home.
  
• 도서관에서는 크게 얘기하면 안됩니다. = It is not allowed to speak loudly in the library.
  
• 신생아들은 딱딱한 음식을 먹으면 안됩니다. = Infants are not allowed to eat solid food.
• 작년까지 학생들은 매점 자판기를 사용해도 됐었습니다 = Until last year, students were allowed to use a stall vending machine.

Spoken form

• TV 봐도 돼요 = You are allowed to watch TV. (You can watch TV.)
• 이 케잌 먹어도 돼요 = You are allowed to eat this cake. (You can eat this cake,)
• 술과 담배는 사면 안돼요 = You are not allowed to buy alcohol and tobacco.
• 어제까지 놀아도 됐었어요 = Until yesterday, I was allowed to muck around.
• 작년까지 빅토리아공원에는 들어가면 안됐었어요 = Until last year, people were not allowed to enter the Victoria park.