If someone asks you to make a program about something, can you do it in any languages that you know without looking into references?

Can you remember all the languages features, because there are features that are not possible in a language that are possible in other languages? For instance, C++ can inherit two classes, and in Java you can't (interface you can). Also you can't initialize an instance variable in C++ if it's not a static const... in Java you can.

I ask this because before I can program in Visual Basic, but now that I'm studying Java, things change - as simple as the syntax for instantiating an object, and I get confused. I need to look at Visual Basic reference just to do it.

Is learning many different programming languages bad? Because I feel that I waste my time learning Visual Basic.

I am mainly C# programmer, but I aslo know VB, Perl, C++, PHP and a bit of java. If I have a problem I can usually solve it in C# and VB without looking into references (of course depending on its complexity). I can also do it in other languages, but often I have to check the language docs (even if I have already done it 1000 times).

I do not think it's bad. Just the opposite - it's good. But remember, that you will never be very good at all of them.