Korean: Verb＋야 되다/하다 | Should, Must

This time, let's learn how to use "verb + 야 되다/하다" to express the meaning of "must" and "should".

Verb + 야 되다 / Verb + 야 하다

Basically, by adding "야 되다" or "야 하다" after the verb, it means "must do..." or "should do...".

 요 type of verb ＋ 야 ＋ "되다" or "하다

The 요 form of a verb is related to the vowel of the stem. For more details, please refer to Korean: About Verb 동사 + 아/어요, 해요.
So it can be further broken down into the following rules. If you have already mastered the variation of 요 type of verbs, you should be able to understand it quickly.

Let's see some examples below. 되다 and 하다 can be used either way.

Prototype, honorific, non-honorific

Let's talk a little bit about the variations of prototypes, honorific types, and non-honorific types. When you want to make a honorific or non-honorific expression, just change the 되다 or 하다 at the end.

Questionable sentences

Let's talk about questionable sentences.For the 해요 type, you only need to raise the final tone (to "요?").
In the case of 합니다, replace 다 with "까? and that's it.

Past tense

For the part about the transitive, there are two verbs in the sentence pattern, so we need to make a little distinction. We have a question: Do we need to change both of them into the past tense? Or should I just change the last one to the past tense?
First of all, 되다/하다 should be replaced with the past tense "됐다/했다" as a correct first step.
Then, it is necessary to refer to whether the action was done or not.
For example,

어제 전화 해야어요.

I had to call you yesterday. (So called)

어제 전화 했어야했어는데.

_I should have called you yesterday. (Because I didn't, so ended with 는데 to express my exclamation.) _

Conclusion.

If the action is completed, the verb's tense is "present tense".
If the action is not completed, the verb's tense is "past tense".

Sentences

사무실로 돌아 가야합니다.

I have to back to the office.

언제까지 여기에 있어야해요?

Until when should I be there?

가족에게 편지를 써야합니다.

I need to write a letter to family.

지난 주말에 숙제를 끝내야했어요.

I had to finish my homework last weekend.

Conclusion

• By adding "야 되다" or "야 하다" after the 요 type of the verb, it can mean "must do... or "should do...".
• The 요 type of the verb is related to the vowel of the stem. Therefore, it is integrated as "verb + 아/어 야 되다/하다".
• For past tense, if the action was not done, both verbs are changed to the past tense. If the action was done, 되다/하다 is replaced with the past tense 됐다/했다.