Cannot Assign because it is a method group C#?

You have to call the AppendText in this way:

textBox1.AppendText("Some text")

Use following

textBox2.AppendText(text);

Instead of

textBox2.AppendText = text;

AppendText is not a property but a method. Thus it needs to be invoked with parameter and cannot be assigned directly.

Properties are special methods, that support assignments due to special handling in compiler.

Do this instead (AppendText is a method, not a property; which is exactly what the error message is telling you):

textBox2.AppendText(text);

textBox2.AppendText(text); is a method. You have to call it like one. You were performing an assignment operation on a method.