Learning a New Programming Language Improves Your Understanding of the Language(s) you Already Know
This is one of those things that people more knowledgeable then you will tell you all the time, but you only realize it after you experience for yourself. I my case, I've been learned JavaScript for almost a year now, and while I did dabble in PHP a bit, I never went deep into PHP, I learned just a few little practical things, PHP is easy to start since simplest hosting solutions all support PHP. I just needed PHP for simple server side stuff, like templates, a few edits to WordPress themese etc. That being said my true second language I'm seriously devoting time and effort to learn is C#. The reason I went with C# is that the company where I work for uses Microsoft stack (.NET MVC, ASP.NET) for it's websites, which all require knowledge of C#. Since I'm more in favor of practical then theoretical knowledge, learning C#, from my point of view, will allow me to gain deeper insight on how the system works in the company I work for, at the moment as a QA test...