"This person needs to read more."
Translation:Этому человеку нужно больше читать.
why not "этот человек должен больше читать"? должен / нужно technically means the same?
Meanings of these words partially overlap, but they're not completely the same.
До́лжен (feminine должна́) usually has the meaning of obligation (я должна́ прийти́ = I must / have to / am to come) or prediction (он до́лжен прийти́ = he will probably come). Ну́жно usually has the meaning of neccessity (мне ну́жно прийти́ = I need to come, I have to come).
I think that would mean something more along the lines of "This person needs to read a lot".