Russian Grammar
Grammar is the basis of any language. To master a language without learning its grammar is only possible for babies and people who isolate themselves away from their native environment. If you don't plan to live in a foreign country for an extended period of time then learning the Russian grammar is essential.
When learning the grammar, you need to memorize the grammar rules. This way you will create in your mind a collection of patterns used to construct correct sentences. Learning the Russian grammar can be considered as acquiring as many patterns as possible. The patterns gradually grow into a habit and you will make a regular thing of using them subconsciously. The best way to learn and review the patterns is to read books in the original.
Basic Principles of Learning the Grammar
Learn the basics of grammar first. You should be able to conjugate verbs, decline nouns and pronouns, and define the sentence structure before going into further details.
Learn grammar rules by remembering the sentences illustrating their usage. It will be easier than memorizing the rules themselves.
Compare foreign grammar rules with those of your own language. This will help you to find similarities, discover the differences, and create associations.
Learn grammar rules along with exceptions to the rules.
Russian for foreigners
Source: masterrussian.com