The Advanced Grammar Challenge was exceptionally perfect! Not only have I learnt the most important grammatical rules and structures, but I've also learnt tons of new expressions through the example sentences.
This challenge contained video and written lessons which helped me learn the pronunciation of the new words and each sentences, and every lesson was clear and well-structured which helped me memorize the rules and grammatical structures. Through the exercises I could practice what I had learnt before.
To sum up, during this course I could totally immerse myself into real life English, as I've heard and read huge amount of advanced sentences used by natives. I can recommend it to anyone! :)