gongchaege oneul iljeongirang yaksok siganeul jeogeo dwosseo.

적어 뒀어 comes from 적어 두었어, which is:

• 적다 = to write down
• 두다 = to put/leave something in a certain state

When -아/어 두다 is added to a verb, it often means do something in advance and leave it that way for later.

So 적어 뒀어 means more than just wrote. It has the nuance of:

• I wrote it down and left it there
• I wrote it down beforehand so I can use/check it later

In this sentence, it suggests the speaker wrote the schedule and appointment times in the notebook for future reference.

Here, 에 marks the place where the writing appears.

• 공책에 적다 = to write in/on a notebook
• 에 is being used like in/on/at

So 공책에 means in the notebook or on the notebook page, depending on how natural English would express it.

If you used 공책을, that would make notebook the direct object, which does not fit this verb in this sentence. You are not writing the notebook; you are writing in it.

이랑 means and or with in casual speech.

So:

• 일정이랑 약속 시간 = schedule and appointment time(s)

It is an informal connector between nouns. Similar alternatives are:

• 하고 = casual and/with
• 와/과 = more neutral/written/formal and/with

So this sentence sounds naturally conversational because it uses 이랑.

Because 오늘 일정이랑 약속 시간 is one combined noun phrase: today’s schedule and appointment times.

The structure is basically:

• 오늘 일정이랑 약속 시간 = schedule and appointment times
• -을 attaches at the end of the whole object phrase

So Korean does not need to mark both nouns separately here. It is natural to put the object marker just once, on the final noun:

• 오늘 일정이랑 약속 시간을 적어 뒀어

This is similar to how English says I wrote down the schedule and the appointment times, where the whole phrase functions as the object.

약속 means appointment, promise, or plans to meet someone, depending on context.

In this sentence, 약속 시간 most naturally means:

• appointment time
• the time of a planned meeting
• when the appointment is

So the speaker wrote down both:

• 오늘 일정 = today’s schedule
• 약속 시간 = the time(s) of appointments/plans

Korean very often omits the subject when it is obvious from context.

So even though English would usually say something like:

• I wrote down today’s schedule and appointment times in my notebook

Korean can simply say:

• 공책에 오늘 일정이랑 약속 시간을 적어 뒀어

The subject is understood from the situation. In conversation, this usually means I, but it could be someone else if the context makes that clear.

적어 뒀어 is casual/informal speech. It is the kind of form you use with:

• close friends
• younger people
• family
• people you speak casually with

A more polite version would be:

• 공책에 오늘 일정이랑 약속 시간을 적어 뒀어요.

A more formal/plain-dictionary-style version could be:

• 공책에 오늘 일정이랑 약속 시간을 적어 두었어요.

So the sentence as given sounds natural and conversational.

뒀어 is the contracted form of 두었어.

So:

• 적어 두었어 → 적어 뒀어

This contraction is very common in everyday Korean. It makes the sentence sound more natural in speech.

Both mean the same thing, but 뒀어 is what you will hear very often in conversation.

Grammatically, 오늘 directly sits before 일정, so at first glance it most clearly modifies 일정.

However, in natural context, many speakers will understand it as applying to the whole set of things being written down, especially if the appointments are part of today’s plans.

So the sentence is naturally understood as something like:

• I wrote down today’s schedule and appointment times in my notebook.

In real conversation, Korean often relies on context more than English does.

Yes. 적어 놓았어 is also possible.

Both -아/어 두다 and -아/어 놓다 can express the idea of doing something and leaving it in that state.

So:

• 적어 뒀어
• 적어 놓았어

can both mean wrote it down and left it there for later.

That said, 적어 두다 is especially common for actions done in advance for convenience or preparation, so it fits this sentence very well.

Yes, that is a very helpful way to read it.

The sentence breaks down like this:

• 공책에 = in the notebook
• 오늘 일정이랑 약속 시간을 = today’s schedule and appointment times
• 적어 뒀어 = wrote down and left there / wrote down for later

So the overall pattern is:

place + object + verb

That is a very common Korean sentence order.