What is the plural form of the word personnel?

Answer 1

the word "personnel" is already in a plural form

This answer is incorrect. The word "personnel" is singular. The plural form of "personnel" is "personnels". Personnel may refer to a group of employees or people, but it is still taken as being a singular noun, much like how you can say "one people". People refers to a group of many more people, but in this sense, "people" is ONE THING. So referring to the word "personnel", it is already singular and the plural form is "personnels".

The second answer above is incorrect. The word personnel was previously only used in the plural sense. There was no singular form of the word - the singular form would be "member of staff" or something like that. It looks like "personnel" is now also being used as singular, which is okay - language changes. But do not try to make personnel plural by adding an S - this is incorrect and never used.

Answer 2

A good sentence for the word personnel is: Sally has her own personnel manager.