Здравствуйте,
Kinra 
Gramatic is hard enough. One more complexity - decline of words. And large and not simple system of formation of verbs and turns on their basis.
живу, пере
живу, до
живу, вы
живу, из
живу, с
живу, от
живу, за
живу, при
живу...
Basis - one word (жизнь). And variants at it... Уйма
But some words have only one meaning, as against other languages
Even I own russian approximately on 60-70 of percents from a maximum
