My biggest fear is once I start to learn another programming language is ill confuse it with the one I already know or have to unlearn habits that work well in my "native" language and it will be hard to go back. How do you guys do it?

Learning one makes it easier to learn another, provided you already know the main concepts of programming in general. I think everyone people gets tripped up with syntax being different on occasion. Personally I experience this going from a language that uses semicolons to one that doesn't, and vice versa.

@Paramite that is true about Python, as well as JavaScript but if it's a non-optional language you're not so lucky. I was referring to transitioning between C# and VB.

I switch between objective c and swift - very different and distinct syntaxes. Sometimes I trip up and use var but it's really not that bad

String answer = "Give it some time! Once you grow as a programmer and the multiple personality disorder kicks in, you'll be able to designate each language to a different persona"; /* Mr. Java Talking At The Moment */

I am most fluent in C, PHP and Perl, but recently started building an app by myself.

That meant PHP, learning Swift, Angular, and dusting off some minor Java experience.

I wont lie to you, I get mixed up sometimes.

A good IDE to snap you back to reality, and TRYING not to work in both languages at the same time (essentially allows me to "switch gears" mentally) helps.

I wish I could double ++ you @Alwaysbusy

Just recap the coding standards when switching to another language and you shouldn't have any issues, it takes 2 minutes and it works for me, hope it will for you too.