sueobi sip bun hue sijakhaeyo.

Korean uses two number systems:

• Sino-Korean (일, 이, 삼, …, 십, …)
• Native Korean (하나, 둘, 셋, …, 열, …)

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.

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.”

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

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

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.”