What are the main programming languages any student should learn? Why?

• one classical compiled language, like C++ or C
• one modern compiled language, like Swift or Go
• one bytecode language, like Java or C#
• one scripting language, like Python or PHP
• one DOM scripting language, like JavaScript

Obviously brother that was C or C++ mother of all language 

It depends. If you are passionate about Web Development, give yourself time to learn Front-end languages like HTML5, CSS and JAVASCRIPT. After that, you should learn back-end server side languages like PHP & SQL. If you are passionate about Mobile App Development, Learn JAVA. If you are into Stastics and data analysis, learn PYTHON.

You have asked what programming language should every student learn? For me i will convince you to use .NET, because i am .NET developer but for you the main thing is that you have to first evaluate/analyze your interest which field of programming language you like more, i mean if your interest is towards graphics/game programming then there are dozens of good programming language and tools for that like Unity #D, Maya, you can also do that in languages like C++, Java, C# and many more, if you like front-end development then there are languages like javascript, css, angular, jquery and many more, if your interest is towards web programming then ASP.NET, PHP, RUBY, JSP and many more, ... and the list goes on. Why i am emphasizing the word your interest, it is the main aspect if you have it on your job or skills you can excel. Best of Luck.   

I believe it's not a main set of languages every student / engineer should acknowledge them, instead it's a set of stacks you can compare between them and finally choose from them, and of course you can combine more than one stack on your toolbox, and another advice about nominating an exact technology, almost all of us will suggest you his/her stack even me, so my advice is compare well between stacks and define first what platform you are targeting to reduce your search circle.and at last for me: I'm a .NET developer writing C# code and contacting MSSQL Server for databases, and sure I've a good development skill set in front-end using JavaScript and JQuery.hopefully this answer could help a little, Good luck. 

Depends on the target catagory.

for desktop applications:

• C#
• Java
• Ruby
• Python

For web applications (Front-Side):

• JavaScript

For web applications (Server-Side):

• PHP
• ASP

For shell scripting:

• Python
• Ruby
• BASH

Notice that there some languages can be used for multiple purposes. Python is used for web applications, desktop applications and shell scripring. There are also some lagnuages used for single purpose. PHP is used for web applications only. 

it's upto the interest of a student...As a beginner it's really the C, C++, the mothers of all languages.I like C,C++ it's really very interesting languages,HTML and CSS are also very useful for Web Development

the language that everyone who wants to become a potential programmer should learn every language that gave him better control on hardware and reliability.

c and c# should be learned by any student because its a basic to approach for any other programming language

First a student have to learn c language, because it is basic pillar to know the coding and here we apply some logics also

you should learn back-end server side languages like PHP & SQL very Easily