-을 것 같다

• ㄹ 것 같다 (-l geot gatda) — after vowel or ㄹ (l)-final stems
• 을 거 같다 (-eul geo gatda), ㄹ 거 같다 (-l geo gatda) — dominant form in colloquial speech

을 (-eul, irrealis attributive suffix) + 것 (geot, “thing”) + 같다 (gatda, “to look like”). Literally "it looks like a thing that [SUBJECT] will..."

• (SK Standard/Seoul) IPA^(key): [ɯɭ kʌ̹t̚ ka̠t̚t͈a̠]
• Phonetic hangul: [을 걷 갇따]

을 것 같다 • (-eul geot gatda)

1. to feel like; to feel that; to think (expresses an assumption, guess, or supposition; also used in hyperbolic statements about one's emotional state)

   이 나무는 쓰러질 것 같았습니다.

   I namu-neun sseureo-jil geot gatatseumnida.

   It seemed this tree would fall down some day.

   아마 아기가 울었을 거 같아요.

   Ama agi-ga ureosseul geo gata-yo.

   I think it's probably the baby who cried.

   그 날은 기분이 좋을 거 같았어?

   geu nar-eun gibun-i joeul geo gatasseo?

   Did you feel like you'd be in a good mood that day?

   너무 일을 많이 해서 죽을 거 같네.

   Neomu ir-eul mani haeseo jugeul geo ganne.

   I've worked so hard, I feel like I'm going to keel over.

   비가 올 것 같다.

   Bi-ga ol geot gatda.

   It looks like it will rain.

   공항까지 지하철을 타면 될 것 같은데 혹시 지하철이 어디 있는지 아세요?

   gonghang-kkaji jihacheor-eul tamyeon doel geot gateunde hoksi jihacheor-i eodi inneunji aseyo?

   I feel that I can take the subway to the airport, do you happen to know where the subway is?

• 나 보다 (-na boda) and 을 것 같다 (-eul geot gatda) both convey the speaker's assumption or guess. However, 나 보다 (-na boda) is more restricted in its semantic scope and can only be used for a supposition (often about a present state) based on evidence gathered at the moment of speech, while 을 것 같다 (-eul geot gatda) has a more subjective nuance. Thus 죽을 거 같아 (jugeul geo gata) means "I feel like [SUBJECT] is going to die", often in a hyperbolic sense, while 죽나 보다 (jungna boda) means "It seems [based on current evidence] that the [SUBJECT] is [currently] dying".
• 을 것이다 (-eul geosida) also conveys an assumption or supposition, but with a much stronger sense of certitude than 을 것 같다 (-eul geot gatda).

• See 같다#Conjugation. As the subject of 같다 (gatda) is always 것 (geot), which can by definition never be honored, the honorific forms do not exist.