Translation of agil

I learned Russian during 8 years in highschool, but since I left school 6 years ago, I have forgotten most of it and did not have opportunity to speak or practice in any way. That's why I am on Vocabulix.
In order to quickly become successful, one would have to change certain points, at least in my opinion: After 5 months of learning, I have still not found the grammar practice on which I should concentrate.
Many thanks for your suggestions. They are very useful. I can't answer your mail now, but I will come back to you later when I'll have more time. I hope that you and your family are well!