本身(běn shēn) - itself, oneself, in itself in Mandarin

本身 (běn shēn) is the emphatic "itself": it separates a thing from its context, its causes or its reputation. 问题本身 is the problem as opposed to the fuss around it, and 钱本身 is money considered apart from what it buys.

It follows the noun it modifies, never precedes it, and it needs no 的. It is equally at home after an abstract noun, a concrete object or a person, and it is very common in argument and analysis.

The trap is mixing it up with 自己 (zì jǐ). 自己 is the reflexive oneself, the doer of an action: 他自己去 means he went himself. 本身 makes no claim about who acts; it isolates the thing under discussion. 他本身是老师 tells you what he is, not what he did.