I agree with this. For me, I'm using the language I'm currently using at work (C#) to learn them better. If I'm going to be tested (in tech interviews) in the language I know my bet is that it'd be better to know the C# way of doing it and knowing how to implement it using C# conventions. I haven't interviewed yet, but this is just the hunch I have if the goal is to do well in a tech interview