what is this
이게 뭐야? *
i-ge mwo-ya? (*to younger person)
이게 뭐에요? **
i-ge mwo-e-you? (**in polite language)

go to sleep
자러 가 *
ja-reo ga
자러 가요 **
ja-reo ga-yo

it's so hot
너무 덥다 *
neo-mu deob-dda
너무 더워요 **
neo-mu deo-wo-yo