saengseoneul guun da-eume baro meogeosseoyo.

After grilling the fish, I ate it right away.

Breakdown of saengseoneul guun da-eume baro meogeosseoyo.

• ~을: object particle
• 먹다: to eat
• 바로: right away
• ~ㄴ 다음에: after

Questions & Answers about saengseoneul guun da-eume baro meogeosseoyo.

Why is it 생선을 and not 생선은?

생선을 uses the object particle -을/를, because fish is what is being grilled and eaten.

• 생선 = fish
• -을 = object marker used after a noun ending in a consonant

So 생선을 구운 다음에 means after grilling the fish...

If you used 생선은, that would mark fish as the topic, which changes the feel of the sentence.

Why is it -을 and not -를?

Korean uses:

• -을 after a noun ending in a consonant
• -를 after a noun ending in a vowel

생선 ends in ㄴ, which is a consonant, so it becomes 생선을.

Why does 굽다 become 구운 here?

This is because 굽다 changes form when it comes before a noun.

Here, it is part of the pattern:

V-(으)ㄴ 다음에 = after doing V

So:

• 굽다 = to grill / roast
• 구운 다음에 = after grilling

This happens because 굽다 is a ㅂ-irregular verb, so the ㅂ changes in this form:

• 굽다
• 구운
• 구워요
• 구웠어요

So 구운 is the correct modifier form here.