Learn Korean: Verb + 아니었어?

Let’s take a look at the Korean sentence pattern Verb + 아니었어(?). We use this when we realized that what we thought was the case changes or turns out to be different or wrong. For example, I was going to meet my friend today and she mentioned that she would come with her new boyfriend. She is so eager to introduce him to me. But when she showed up, she was alone. So I said I thought you were coming with your boyfriend. The main verb is 남자친구랑 같이 오다 (to come with a boyfriend). We take the verb stem (오) and attach 는 것 (오는 것). 것 is often simplified into 거. Then, we add 아니었다. The actual sentence is 남자친구랑 같이 오는 거 아니었어(요)? Here's another example in past tense. I went to Namsan with that same friend and I told her to upload the best shot tonight. She said she would as soon she got home. Around midnight, I scanned her Instagram because I thought she would upload it there. I texted her that I couldn’t find her post on Instagram. She replied that she uploaded it on Facebook. I was wrong so I said I thought you uploaded it on Instagram. The main verb is 인스타에 올리다 (to upload on Instagram). We take the verb stem (올리) and attach ㄴ 것 (올린 것). If the verb stem ends in a consonant, use 은 것. Then we add 아니었다. The actual sentence is 인스타에 올린 거 아니었어(요)? It is essential that we know how to conjugate verbs in their (ㄴ/은/는/ㄹ/을) + 것 form.

서울에 사는 거 아니었어?

I thought you live in Seoul.

집에 간 거 아니었어?

I thought you went home. (I am surprised you are here in the club too)