Its like the word family. It refers to a group of people (plural) but is a the noun personnel is singular.
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.
plural
The word team is singular; the plural form is teams.
These is plural, this is singular
if a word refers to a single item it is singular. if it refers to lots of things it is plural."Potato" is singular "potatoes" is a plural word."mouse" is singular, "mice" is a plural word."person" is singular, "people" is a plural word.
The word 'she' is in singular form. The plural for 'she' would be 'they'.
"Have" may be singular or plural: I have; we have.
The word metastasis is singular, metastases is plural.
No, the word "list" is singular. The plural form of "list" is "lists."
Caveman is singular. Cavemen is plural.
Verbs cannot be singular or plural. Has is after singular nouns.
It's singular. The plural is cafeterias.