The answer is b-a-l-a-n-c-e dude.
Learn grammar while learning new words.
Simple and clear.
The guy has to learn at least 3,000 words in order to speak Russian.
If the knowledge of word is not accompanied with the knowledge of grammar it will be exactly like singing separate notes instead of singing whole musical pieces.
I was taught 6 languages and in all cases grammar was the number one.