I understand that the forms "als ob..." and "als wenn..." are grammatically used in the same way. But are they completely interchangeable? What is their difference?
For example, are both of the following correct? Do they sound different?
Er tut immer so, als ob er Chef wäre.
Er tut immer so, als wenn er Chef wäre.
I am not sure that my "als wenn" example is correct.