I arrived home to (discover) the smell of something tasty.
아침에 일어나니까 선물이 있었어요.
When I wake up in the morning, the gift had already arrived.
집에 오니까 밤 12시였어요.
When I arrived home, it was midnight.
-(으)니까 expresses the discovery of tie fact described in the second clause as the result of performing the action described in the first clause. It corresponds to ‘when’ or ‘(do something) only to discover’. If the verb stem ends in a vowel, -니까 is used, and if it ends in a consonant, -으니까 is used. This form of -(으)니까 denoting discovery attaches only to verbs.
When -(으)니까 expresses the result of an action (discovery), -았 and -겠 cannot precede it.
• 아침에 회사에 갔으니까 아무도 없었어요. (X)
->아침에 회사에 가니까 아무도 없었어요. (O)
I arrived at the office only to discover that nobody was there.
• 저녁에 집에 왔으니까 어머니가 계셨어요. (X)
->저녁에 집에 오니까 어머니가 계셨어요. (〇)
When I arrived home in the evening, my mother was there.
(Compare with “-(으)니까: Reasons and Causes ” here)
A: 제이슨 씨한테 전화해 봤어요? Did you call Jason on the phone?
B: 네, 그런데 전화하니까 안 받아요. Yes, but only to find he did not answer.
A: 그 모자 얼마예요? How much was that hat?
B: 만 원이요. 어제 백화점에 가니까 세일을 하고 있었어요.
10,000 won. When I went to the department store yesterday, they were having a sale.