This isn't a foreign language, it's a computer language. Especially for business programming, it should be about week and a competent programmer should be able to write decent code with a manual or a web page open.

Most of the code I write is in python or java. But I'm writing a small windows application, and chose C#: I installed the IDE, and I was writing code in a few days, especially with google helping out.

When needed I write C and C++ as well, again not a big deal except it takes a lot more time to get the same amount of work done, but sometimes there's a library you need to link to.

The caveat in all of this is you need to be competent.