1) こい！ koi
both mean 'come here' but #2 is much more polite being cushioned by many soft, indirect words. One of these words is ちょっと.
ちょっと means 'little' or 'small amount' but it is often used to soften an otherwise painful 'no' or 'your request is impossible; live with it'
chotto muzukashi desu ga.
That's a little difficult. (this may be said when the request is impossible)
chotto dekinai desu.
It can't be done.
chotto wakaranai desu.
I'm not really sure.
I have been told the sound 'chotto' is a bad word in Korean. If that is the case, chotto may not be that soft of a word...