Websites to learn almost anything for free

Here is a list of websites where you can learn almost anything for free.

In some of the websites, you don't even have to register at all, just link your Facebook or Twitter account in order to get started.

All of the subjects taught in these websites are provided free of charge and free of ads.

1. Memrise

Subjects taught: almost everything

Pros: The format is flashcards that contain mnemonic devices.

Cons: It does not help when it comes to learning grammar or formulae.

2. Coursera

Subjects taught: college-level courses

Pros: A user can get "statement of accomplishment" provided by the university at the end of each course.

Cons: The serious format could turn off some leisure-learners.

3. Duolingo

Subjects taught: six European languages (as of 2014).

Pros: can skip classes based on the level a person has previously attained.

Cons: as of 2014, there are only six languages.

4. Codecademy

Subjects taught: programming languages

Pros: One of the best programming language-learning websites for novice programmers.

Cons: It only teaches some basic programming languages such as Python, Ruby, Javascript, et al.

5. Khan Academy

Subjects taught: almost everything

Pros: The lectures are given in mostly didactical basis.

Cons: Too lecture-oriented

*I will add more websites to this list as soon as I find them. If you have any suggestions on free websites for learning, feel free to drop a comment!