안녕 요미야.. 없어 is the present form of the verb 없다, which means to not exist. 수 means capability/ability. When it is used with 없어다.. i.e. 수 없어, this translates to.. ablity not exist ~ cannot do, or not able to. 먹을 수 없어, I can't eat (I don't have the ability to eat). 없어 simply expresses the non-existance of something (now). Yeh? Your friend asks you.. hey Yume! Do you have $10 on you?. You can say.. 야! 돈 없어! Which means, money doesn't exist ~ you don't have money. I find some verbs have slight past and future, or progressive tones (that differ to english).. so maybe someone can expand on that too.