Usually, these words are fairly interchangeable, however this is not always the case. Sometimes "staff" can mean office workers, while "personnel" can mean the entire body of employees. It just depends on the company and how they choose to categorize people. Buona fortuna! Greg

Yes, 'personnel', as a collective noun, can mean 'staff', but I wouldn't say that they are always interchangeable. 'Staff' are employees, but that isn't always the case for 'personnel'. In fact, the commonest collocation with 'personnel' is actually 'military personnel'. We use 'personnel' in this context for the body of people who work for an organisation (i.e. the army) in professional capacity, but who are not employees, as such.

Yes, you are right - 'personnel' is a slightly more formal version of the word 'staff' and in the sentence you gave they are interchangeable. Bob