What is the equivalent of a 'friend' keyword in C Sharp?

What is the equivalent of a 'friend' keyword in C Sharp?

How do I use the 'internal' keyword?

I have read that 'internal' keyword is a replacement for 'friend' in C#.

I am using a DLL in my C# project that I have the source code for and yet I do not want to modify the existing code. I have inherited the class and I can use my inherited class any way I want. The problem is that most of the code in the parent class has protected methods. Will using a friend somehow make it possible to access or call these protected methods?