oneul bumonimkke gwaireul sa deuryeosseoyo.

부모님 includes the honorific suffix -님, which adds respect.

• 부모 = parents, a neutral/formal word
• 부모님 = parents, but respectfully

Since the sentence is about doing something for one’s parents, 부모님 is the natural choice. In Korean, family members are often referred to respectfully, especially parents.

께 is the honorific version of 에게 or 한테, which mean to or for.

So:

• 부모님께 = to/for my parents, respectfully
• 친구에게 / 친구한테 = to/for a friend

Because the receiver of the action is someone respected, 께 is the right particle here.

It is built from:

• 사다 = to buy
• -아/어 드리다 = to do something for someone respected
• -었어요 = past tense polite ending

So:

• 사 드리다 = to buy for someone respected
• 사 드렸어요 = bought for someone respected

The 드리다 part adds the idea of doing the action for the other person, with respect.

Both can mean doing something for someone, but 드리다 is the humble/respectful version of 주다.

Compare:

• 사 줬어요 = bought for someone
• 사 드렸어요 = bought for someone respected

When the person receiving the action is your parents, teacher, customer, etc., 드리다 is much more appropriate.

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

So this sentence does not explicitly say I, but the implied subject is usually:

• 저는 or 제가 = I

A full version could be:

• 저는 오늘 부모님께 과일을 사 드렸어요.

But in natural Korean, leaving it out is very common.

을/를 marks the direct object of the verb.

Here, 과일 is the thing that was bought, so it gets the object particle:

• 과일을 = fruit (as the object)

So the sentence structure is basically:

• 오늘 = today
• 부모님께 = for my parents
• 과일을 = fruit
• 사 드렸어요 = bought for them

Usually 과일 means fruit in a general sense, or some fruit, depending on context.

Korean often does not force you to mark singular vs. plural the way English does.

So 과일을 사 드렸어요 could mean things like:

• bought some fruit
• bought fruit
• bought a fruit item

If you want to be specific, Korean usually names the fruit and quantity:

• 사과 한 개를 사 드렸어요 = I bought one apple for them
• 바나나를 사 드렸어요 = I bought bananas for them

Time words like 오늘, 어제, and 내일 often appear without any particle.

So:

• 오늘 부모님께 과일을 사 드렸어요. = natural
• 오늘에 = usually unnatural in ordinary speech

If you want contrast or topic marking, you can add 은/는:

• 오늘은 부모님께 과일을 사 드렸어요. = As for today, I bought fruit for my parents.

But with no special contrast, just 오늘 is normal.

Yes, to some extent. Korean word order is flexible because particles show each word’s role.

These are all possible:

• 오늘 부모님께 과일을 사 드렸어요.
• 부모님께 오늘 과일을 사 드렸어요.
• 과일을 오늘 부모님께 사 드렸어요.

The verb usually stays at the end, but earlier parts can move around for emphasis or flow.

Still, the original order is very natural and straightforward.

It is polite everyday speech.

The politeness comes from several parts:

• 부모님 = respectful noun
• 께 = honorific particle
• 드리다 = humble/respectful verb
• -어요 = polite speech ending

So this is respectful but not stiff.

A more formal version would be:

• 오늘 부모님께 과일을 사 드렸습니다.

Not if you want to mean I bought fruit for my parents.

사다 by itself just means to buy. It does not naturally express the benefactive idea buy for someone with 께 in this way.

So these are better:

• 오늘 부모님을 위해 과일을 샀어요. = I bought fruit for my parents.
• 오늘 부모님께 과일을 사 드렸어요. = I bought fruit for my parents.
  (more natural when emphasizing doing it for them respectfully)

So 사 드리다 is the key form here.

Because 드리다 is functioning like a helper verb after 사다, and in standard learning materials this is usually written separately:

• 사 드렸어요

In casual writing, you may sometimes see:

• 사드렸어요

But if you are studying standard written Korean, 사 드렸어요 is the safer form to use.