The Colloquial Style
This is the style of informal, friendly oral communication. The vocabulary of colloquial style is usually lower than the formal or neutral styles, it is often emotionally coloured.
Colloquial speech is characterized by the frequent use of words with a broad meaning (широкозпачные слова): speakers use a small group of words in different meanings, whereas in a formal style (official, business, scientific) every word is to be used in a specific and clear meaning.
There are phrases and constructions typical of colloquial type: What's up?(= What has happened); so-so (=not especially good); How are you doing? (= How are things with you?); Sorry? Pardon ?( = Please, repeat, Ididn't hear you); See you ( = Good-bye), etc.
In grammar there may be: a) the use of shortened variants of word-forms, e.g. isn't, can't; there's ; I'd say ; b) the use of elliptical sentences — Like it? (= Do you/Did you like it?) — Not too much (= I don 't like it too much); May I?(= May I ask a question/do this?).
The simple sentences and asyndetic connection between the parts of sentences is used in the syntax of colloquial speech. Complex constructions with non-finite forms are rarely used.
Familiar-Colloquial Style and Slang (фамильярно-разговорный стиль, жаргоны)
The familiar-colloquial style used in very free, friendly, informal situations of communication (between close friends, members of one family, etc.). Here we find emotionally coloured words, low-colloquial vocabulary (просторечная лексика) and slang words. This style admits also of the use of rude and vulgar vocabulary, including expletives /obscene words /four-letter words /swearwords (бранная лексика).
Some examples of familiar-colloquial/low-colloquial words (also called 'slang'):
Rot/trash/stuff ( = smth. bad); the cat's pyjamas (=just the right/suitable thing); bread-basket (= stomach).
The term slang is used in a very broad and vague sense. Besides denoting low-colloquial