Changing your mind
My thoughts have changed
Textbook생각이 바뀌었습니다saeng-gak-i ba-kkwi-eot-seum-ni-da
Real아, 생각해 보니까... / 다시 생각해 봤는데a, saeng-gak-hae bo-ni-kka... / da-si saeng-gak-hae bwan-neun-de
~해 보니까 (now that I tried/thought about it) is how you justify a mind change. Koreans often soften flip-flopping with 다시 생각해 보니까 (on second thought). It's normal — Koreans call it 변덕 (fickleness) and it's endearing among friends.
Saying you're not sure
I am not sure
Textbook잘 모르겠습니다jal mo-reu-get-seum-ni-da
Real글쎄... / 잘 모르겠는데geul-sse... / jal mo-reu-gen-neun-de
글쎄 (well/hmm) is the perfect Korean hedge. It buys time AND signals uncertainty. Adding ~는데 at the end leaves the sentence open, like "I'm not sure but..." — inviting the other person to convince you.
Politely disagreeing
I think differently
Textbook저는 다르게 생각합니다jeo-neun da-reu-ge saeng-gak-ham-ni-da
Real음... 근데 나는 좀 다른데 / 그건 좀 아닌 것 같아eum... geun-de na-neun jom da-reun-de / geu-geon jom a-nin geot gat-a
Direct disagreement is uncomfortable in Korean culture. 좀 (a bit) + ~것 같아 (I think/it seems) softens everything. 그건 좀 아닌 것 같아 literally means "that seems a bit not-right" — the Korean art of gentle rejection.
Strongly agreeing
I think so too
Textbook저도 그렇게 생각합니다jeo-do geu-reo-ke saeng-gak-ham-ni-da
Real완전 공감 / 인정wan-jeon gong-gam / in-jeong
공감 (empathy/agreement) is huge in Korean culture. 완전 공감 (totally relate) is the Instagram comment you'll see thousands of times. 인정 (acknowledged) went from formal to meme-tier casual slang.
Asking for a charger
Would you lend me a charger?
Textbook충전기를 빌려 주시겠습니까?chung-jeon-gi-reul bil-lyeo ju-si-get-seum-ni-kka?
Real혹시 충전기 있어요? / 충전 좀 할 수 있을까요?hok-si chung-jeon-gi it-seo-yo? / chung-jeon jom hal su it-seul-kka-yo?
혹시 (by any chance) is the Korean softener supreme. It turns any question from demanding to gentle. 혹시 + question is the formula for asking strangers anything. Korean cafes often have charging cables available — just ask.