Assigning multiple roles to a user

Is what you really mean that you want to give one person the capabilities associated with two roles (but that s/he will still have just the one role)?

If so, you need a user role management plugin, like Capability Manager Enhanced.

Thanks for reply, actually I am trying to give only one member to create and edit posts on my website. At the same time I don’t want to change his/her membership level.

I thought that I can do that by adding custom capabilities ? like creating/editing posts ?

Is it possible ?

Thank you

Yes, using the plugin I mentioned.

this plugin might be easier for what you need, allows you to easily add multiple roes per user

https://www.ads-software.com/plugins/role-includer/

sam