"It depends on the person" is the expression you mean (not 'a person') These are some close alternatives. "It's different for everybody" "It differs from person to person"

Out of context the phrase sounds a bit off, but it is possible, for example "It depends on a person I met last week". Without specifying this INDEFINITE person (because you use the indefinite article) it needs some context... anyway I digress... How about: It's up to someone I met last week. It depends if a person I met last week can do it. I am relying on someone I met last week. I am sure there are a few more, perhaps some more context would help! EDIT: I read the "it depends" in the use of "it's dependent on" not when we talk about generic situations eg "It depends who you talk to"... even more reason for always giving context! EDIT Thanks for the context Victoria! For example, I was asked if all only children are spoilt. And I want to say that it really depends on THE [person/individual]. Some people I know, who are an only child in the family, are not spoilt at all and (but) some are. Rephrase? And I want to say that you can't tell, everyone is different. And I want to say that there is no universal answer. And I want to say that there is no fixed answer to this.

Here is the context: For example, I was asked if all only children are spoilt. And I want to say that it really depends on a person. Some people I know, who are an only child in the family, are not spoilt at all and some are.

Was this written by a native speaker? It doesn't sound natural to me. Or was it perhaps "it depends on the person"? Or was it part of a bigger sentence?