Can someone explain the difference to me between:------

[sweetheart]

companies and company's?

I am updating my cv - how do I write this when I'm saying things like

my role is to administer the companies HR
or
monthly reviews of the companies performance

ta muchly
x

Companies is the pleural of company and would indicate more than one company. If you are referring your own company in the sense of HR or Mission statement or policy correct English would be company's

'companies' is the plural of 'company', so should be used when you're talking about more than one company.

'company's' is the possessive form, so is the form you're looking for (you administer the HR belonging to the company, and review the performance of the company).

one company:

my role is to administer the company's HR
or
monthly reviews of the company's performance

more than one compnay at a time:
monthly reviews of the companies' performance
or
my role is to administer the companies' HR

Each time you need an apostrophe, to show it's the HR belonging to the company/companies, but the words changes depending on how many companies there are.