Does SoloLearn cover all aspects in each programming language?? If not, then in which extent?

Answer 1

SoloLearn definetly covers the basic aspects of the available programming languages.

In addition you have Code Coaches (practical training) to practice actually coding.

But of course it can not cover EVERY aspect of a origrammung language, if you wanna learn a very specific aspect you should search on other platforms e.g. github, stackoverflow, google..