A complete sentence in English consists of a subject (usually a noun) and a predicate (a verb). True, there are minor types like 'Hi!' and elliptical answers to questions like 'Tomorrow', but they are not typical complete sentences in English.
In Russian, on the other hand, there are many major sentence types that do not consist of the familiar Nominative subject plus verb predicate.
There are three kinds of words that make predicates in Russian:
  • verbs proper
  • short adjectives
  • predicatives (including o-forms)
When you read mature Russian prose, with its long sentences and variety of word-orders, you have to keep your eyes peeled for these elements and recognize what type of sentence you're dealing with. All long sentences can be reduced to several types: