1. Style
The study of dialects is further complicated by the fact that speakers can adopt different styles of speaking.
You can speak very formally or very informally, your choice being governed by circumstances.

2. Ceremonial occasions almost invariably require very formal speech, public lectures somewhat less formal, casual conversation quite informal, and conversations between intimates on matters of little importance may be extremely informal and casual

3. Register
Registers are sets of language items associated with discrete occupational or social groups.
Surgeons, airline pilots, bank managers, sales clerks employ different registers.

4. People participating in recurrent communication situations tend to develop similar vocabularies, similar features of intonation, and characteristic bits of syntax and phonology that they use in these situations.
This kind of variety is a register.

5. Lingua Franca
A language that is adopted as a common language between speakers whose native languages are different.

6.  Pidgins and creoles
A pidgin is a language with no native speakers: it is no one’s first language but is a contact language.
It is a simplified speech used for communication between people with different languages

7. Pidgins Origin: from a Chinese attempt to pronounce the English word business during trades in the Far East.
Arises with an urgency of communication to serve specific needs between social groups that are ethnically and linguistically different from each other.

8. One of these groups is in a more dominant position than the other; the less dominant group is the one which develops the pidgin.

9. Characteristics
Pidgin and creole languages are distributed mainly in places with direct or easy access to the oceans.
Consequently, they are found mainly in the Caribbean and around the north and east coasts of South America.
heir distribution appears to be fairly closely related to long-standing patterns of trade, including trade in slaves

10. The sounds of a pidgin or creole are likely to be fewer and less complicated in their possible arrangements than those of the corresponding standard language.
In pidgins and creoles there is likely to be a complete lack of inflection in nouns, pronouns, verbs, and adjectives. Nouns are not marked for number and gender, and verbs lack tense markers.

11. Transitive verbs, that is, verbs that take objects, may, however, be distinguished from intransitive verbs, that is, those that do not take objects, by being marked.
Pronouns will not be distinguished for case, so there will be no I–me, he–him alternations.

12. Syntactically, sentences are likely to be uncomplicated in clausal structure. The development of embedded clauses, e.g., of relative clauses, is one characteristic of the process of creolization: pidgins do not have such embedding.

13. The vocabulary of a pidgin or a creole has a great many similarities to that of the standard language with which it is associated.
However, it will be much more limited, and phonological and morphological simplification often leads to words assuming somewhat different shapes.

14. A pidgin or creole may draw on the vocabulary resources of more than one language.

15. Differences between Pidgins and Creoles:
Pidgin is a combination of two or more other languages and is used for communication among people.
It can be called business language and it is not a first language.
A creole, however, is a language that was at first a pidgin but has “transformed” and become a first language.

16. Syntactic difference: Creole languages have the “Subject Verb Object” word order whereas Pidgin can have any possible order.