The form -아/어 보이다 is one you can use to indicate your own conjecture or feelings on something or someone. This conjecture or feelings are based on outward appearances. This is a rather simple form to use that you can quite easily learn in a few ten minutes. Though there are still a few things you need to keep in mind.
As mentioned the form -아/어 보이다 is used to express your conjecture or feelings on something or someone based on the outward appearance. Therefore the likelihood of the conjecture being mistaken is still reasonable. However, when this form implies that you are nonetheless certain of your conjecture. Other forms are more suitable when you are less certain; forms such as.
Because of the certainty with which you express your conjecture, it might sound a bit too direct. Therefore Koreans oftentimes combine this form with the form -(으)ㄴ/는 것 같다 to soften its directness by adding a feeling of uncertainty.
가: 안나 씨, 얼굴이 많이 아파 보여요.
나: 독감에 걸린 것 같아서 병원에 가야 해요.
A: Anna, you look very sick.
B: I think I got the flu so I need to go to the hospital.
How To Use
Using the -아/어 보이다 is not that difficult as long as you keep the basic rules of Korean conjugation in mind. As you can notice, this pattern follows the -아/어 conjugation rules. This means you will have to keep certain Korean irregular verb groups in mind such as the ㅡ irregular verbs. However, that shouldn’t pose any issue. After attaching the form -아/어 보이다 to the verb, do not forget to conjugate the verb 보이다!
Lastly, you can only use this form with adjectives; using the form with verbs is grammatically incorrect. For verbs, you can use the similar form -(으)ㄴ/는 것 같다.