Learn Hardcore Korean: sueobi sip bun hue sijakhaeyo.

When you count minutes with 분, you always use the Sino-Korean system. So you say 일 분, 이 분, …, 십 분, 이십 분. Although you might hear 열 분 in very casual speech, the standard form with the 분 counter is 십 분.

What’s the role of the -에 after 후 in 십 분 후에?

In Korean, to turn a noun into a time-point expression you attach the particle -에 (at/on). Here:

후 (後) is a noun meaning “after.”
-에 marks it as the time when something happens.

So 십 분 후에 literally means “at after ten minutes,” i.e. “after ten minutes.”

What does the particle 이 do in 수업이 시작해요?

이 is the subject-marking particle. It tells you that 수업 (“class/lesson”) is the subject of the verb 시작해요. You could swap it with the topic particle 은 (수업은) for a slight nuance, but 수업이 is the neutral way to mark “class” as the thing that’s starting.

How do you get 시작해요 from 시작하다?

시작하다 is a 하다-verb (“to start/begin”). To make the polite present tense:

Remove -다 → 시작하
하다-verbs change 하 to 해 when followed by -요
Add -요 → 시작해요

What speech level is 시작해요, and how does it compare to 시작합니다?

시작해요 is the polite-informal style (해요체), suitable for everyday polite conversation.
시작합니다 is the polite-formal style (합니다체), used in formal presentations, announcements, or very polite contexts. Both mean “(I/it) start(s).”

Can 십 분 후에 come at the beginning of the sentence?

Yes! Korean word order is flexible with time expressions. You can say either:
• 수업이 십 분 후에 시작해요.
• 십 분 후에 수업이 시작해요.
Putting 십 분 후에 first often makes the time frame slightly more prominent.

How is 수업이 십 분 후에 시작해요 pronounced and romanized?

Pronunciation tip: link sounds smoothly.
IPA (approximate): [su͈ʌ̹pi ɕippu̟n hu̟e ɕid͡ʑa̹gha̠jo̞]
Romanization (Revised): su-eop-i sip-bun hu-e si-jak-hae-yo

Are there other ways to say “after ten minutes” in Korean?

Yes. You can swap 후에 with other “after” expressions:
• 십 분 뒤에 – 뒤 is the native Korean word for “after.”
• 십 분 지나서 – 지나서 means “after passing [that time].”

All three—십 분 후에, 십 분 뒤에, 십 분 지나서—mean “after ten minutes.”