In my opinion, 毫无价值 is more suitable for describing things. If you want to express somebody is useless, you can use '一无是处'. You can use '对我毫无价值' to describe a person or thing which is worthless to you.

"毫无价值'形容一个人的时候,通常指的是,这个人没有可利用的特点. 含贬义,要慎用. "我的价值"虽然有好多人都这么说,但是把价值与人连系起来,始终让人觉得不对劲儿. 人生的价值,生命的价值 更正确一些.

the word 价值 in chinese is too much official, usually a term of politics or finance. such as 商品的价值 the value of the product . if we want to show sb. is useless or can't help at all,we usually say 你真没用! and 你真没用 mostly shows our complaination and the doubtness about the person's ability .if a mom says 你真没用to his son who just got a poor mark，it means why can't u work hard ? but be careful when u use 你真没用 it's exthemily rude .and never say it to your boyfriend. the second situation is that 他一点儿价值也没有 for examble , if someone want to take advantage of the power or money of another one ,he paid a lot but get nothing he may complain about this to a friend: 他根本一点价值也没有！根本 means totally an other situation we say about 价值is that if you got a lv bag at a very low price ( of course it can't be a fake one] you are happy and exciting and may show this bag to ur friend ,you may say :看,我刚淘到的lv包包，才一千块，很值吧？then ur friends say :太值了！ 我终于明白我的价值了 meas finally i know what i can contribute to . always you strugled and confused a lot before u got it

um ~~i thhink you can and you can almost "He is a worthless person" it is just to you not to himself

1.yes，u can use 毫无价值 to describe people,most chinese understand ur meaning,but chinese seldom use 毫无价值 to show people worthless.u can use this words 没用，for example 他是个很没用的人 我很没用。 毫无价值often mean somethings have no meaning or value，for example 他死的毫无价值； 对他来说，这篇文章毫无价值。 ur using 毫无价值 have some mistakes，Joseph木匠's words is right. 2. 我终于明白了我的价值 this is right .