After having added a few hanja characters to the collection, it is time to return to Korean grammar with a new way to express obligations. The Korean grammar expression I want to discuss is -아/어야 되다/하다. I think this is probably the pattern I like using the mosts. Let’s take a necessary look.
Need to -아/어야 되다/하다
The expression -아/어야 되다/하다 might seem difficult, but, in fact, it isn’t at all. You use this expression to express an obligation or a necessity to do something; or the necessity of a certain condition. When you translate a sentence with this Korean grammar pattern, you can do so with “must”, “ought to be”, “have to”, etc. Let us look at an example:
Example: 우리 집이 더러워서 청소해야 해요.
Translation: My house is dirty so I have to clean it up.
While you might suspect it, there is little difference between using 되다 or 하다. The choice of verb is merely up to your own preference at that time. I tend to use 하다 far more than 되다.
How To Use
While the form might seem complicated, it isn’t really that complicated. Perhaps you have already noticed, but -아/어야 되다/하다, follows the same basic principles you’ve seen for the present tense. This means you need to look at the verb stem, more specifically the vowels in it. The rules are:
- If the verb stem contains ㅏ or ㅗ, you use -아야 되다/하다.
- If not, you use -어야 되다/하다.
- For 하다 verbs, the form you use, is 해야 되다/하다.
After you added this, the new added verbs 되다/하다 are conjugated further. Therefore the past tense of this pattern is -아/어야 됐다/했다.
Unlike the previous demands and permissions pattern -마세요 & -지 마세요, you can use this Korean grammar pattern with both verbs and adjectives. You needn’t turn the adjectives into verbs for this pattern.
-아/어야 되다/하다 is one of the grammar patterns in Korean which has not one, but two negative forms: -지 않아도 되다 and -(으)면 안 되다. The first has meaning of something not being necessary, while the latter has the meaning of prohibiting a certain action or behaviour. We will discuss these patterns.