yaksok sigani bakkwieosseoyo.

The appointment time has changed.

Breakdown of yaksok sigani bakkwieosseoyo.

• ~이: subject particle
• 시간: time
• 약속: appointment
• 바뀌다: to change

Questions & Answers about yaksok sigani bakkwieosseoyo.

What does the particle 이 in 시간이 do? Could I use 은/는 instead?

• 이/가 marks the grammatical subject. Here, 시간이 marks “time” as the thing that changed.
• You can use 은/는 to make “appointment time” the topic/contrast:
  • Neutral/new info: 약속 시간이 바뀌었어요.
  • Contrast/topic: 약속 시간은 바뀌었어요. (As for the appointment time, it changed… [implying contrast, e.g., the place didn’t].)
• Subtlety: 이/가 often introduces or focuses on new information; 은/는 sets up a known topic or contrast.

Why is there a space between 약속 and 시간? Is 약속시간 okay?

• Standard spacing treats this as “time of the appointment” (약속의 시간), so write it with a space: 약속 시간.
• You will see 약속시간 in casual writing, but formal writing and tests prefer the spaced form: 약속 시간.
• The particle attaches without a space: 약속 시간이 (not “약속 시간 이”).

What’s the difference between 바뀌다 and 바꾸다?

• 바뀌다 = to be changed (intransitive/passive). No agent stated.
  
  • 약속 시간이 바뀌었어요. (The time has changed.)
• 바꾸다 = to change (transitive/active). Someone changes something.
  
  • 제가 약속 시간을 바꿨어요. (I changed the appointment time.)

What tense/aspect is 바뀌었어요? Does it imply it’s still changed now?