oneureun ppallaega manhaseo setakgireul du beon dollyeoyo.

은 is the topic marker. In 오늘은, it sets today as the topic or frame for the sentence:

• 오늘은 = as for today / today
• It gives a slight contrastive feeling, like today, at least or today in particular

So the sentence is not just saying something happened today. It is more like:

• Today, there is a lot of laundry, so I run the washing machine twice.

You could say 오늘 빨래가 많아서..., but 오늘은 sounds more natural when setting the scene.

Because 많다 works with 이/가, not 을/를.

• 빨래가 많다 = there is a lot of laundry / the laundry is a lot
• 을/를 marks a direct object, but 많다 is not a verb that takes a direct object in Korean

So:

• 빨래가 많아요 = correct
• 빨래를 많아요 = incorrect

This is a very common pattern in Korean:

• 사람이 많아요 = There are many people.
• 문제가 많아요 = There are many problems.

빨래 usually refers to laundry or washing clothes.

Depending on context, it can mean:

• the clothes to be washed
• the act of doing laundry

In this sentence, 빨래가 많아서 means there is a lot of laundry.

So here 빨래 is best understood as laundry/clothes to wash, not the action itself.

-아서 / -어서 connects two clauses and often means because, so, or and then depending on context.

Here it expresses a reason:

• 빨래가 많아서 = because there is a lot of laundry
• 세탁기를 두 번 돌려요 = I run the washing machine twice

So together:

• Because there is a lot of laundry, I run the washing machine twice.

A useful note:

• When -아서/어서 gives a reason, it often sounds natural and conversational.
• It is very common in everyday speech.

Because 세탁기 is the direct object of 돌리다 here.

• 세탁기 = washing machine
• 세탁기를 돌리다 = to run the washing machine

So 를 marks the thing being operated.

Even though English often says do laundry, Korean commonly says run the washing machine in this kind of context.

Yes, 돌리다 literally means to turn, to spin, or to make something go around, but it is also commonly used to mean to run/operate a machine.

So:

• 세탁기를 돌리다 = to run the washing machine
• 선풍기를 돌리다 can mean to run a fan
• 기계를 돌리다 = to operate a machine

It sounds completely natural in Korean. Even though the literal image is spinning/turning, the natural English translation here is run the washing machine.

Because Korean numbers often change form before counters.

The basic number is:

• 둘 = two

But before many counters, it becomes:

• 두

So:

• 두 번 = two times

This is a standard pattern with native Korean numbers:

• 하나 → 한
• 둘 → 두
• 셋 → 세
• 넷 → 네

Examples:

• 한 번 = once
• 두 번 = twice
• 세 번 = three times
• 네 번 = four times

번 is a counter meaning time/occurrence.

So:

• 한 번 = one time / once
• 두 번 = two times / twice
• 세 번 = three times

In this sentence:

• 세탁기를 두 번 돌려요 = I run the washing machine twice

It counts how many times the action happens.

The dictionary form is 돌리다.

To make the polite present form:

1. Remove -다 → 돌리
2. Add -어요
3. 돌리어요 contracts to 돌려요

So:

• 돌리다 → 돌려요

This happens because 이 + 어 often contracts to 여.

A few similar examples:

• 가르치다 → 가르쳐요
• 빌리다 → 빌려요

So 돌려요 is just the normal polite present form.

Korean often leaves out the subject when it is obvious from context.

So even though I is not explicitly stated, the sentence naturally means:

• I run the washing machine twice

In everyday Korean, saying 저는 or 제가 is often unnecessary unless you want emphasis or contrast.

For example:

• 오늘은 빨래가 많아서 세탁기를 두 번 돌려요. = Today there is a lot of laundry, so I run the washing machine twice.

Adding 저는 is possible, but not necessary:

• 저는 오늘은 빨래가 많아서 세탁기를 두 번 돌려요.

That sounds more explicit, but usually the shorter version is more natural.

돌려요 is the polite informal style, which is very common in everyday conversation.

So the full sentence is polite and natural for normal speech:

• 오늘은 빨래가 많아서 세탁기를 두 번 돌려요.

In casual speech, you could say:

• 오늘은 빨래가 많아서 세탁기 두 번 돌려.

Changes:

• 세탁기를 → 세탁기: object marker may be dropped in casual speech
• 돌려요 → 돌려: casual ending

In plain dictionary-style or written statement style, it would be:

• 오늘은 빨래가 많아서 세탁기를 두 번 돌린다.

So 돌려요 is a good standard conversational form to learn.