1. When I came here, they were still discussing the final question

The word "grammar" comes from the Greek word "grapho-technik" (to write correctly) and it originally meant the art of writing which was to give rules of writing and speaking correctly. In general, grammar studies the grammatical structure as a whole system of means used to connect words in the course of speech.

For ex.:
1. When I came here, they were still discussing the final question.
2. I come here they be still discuss final question.
In the second case there is no connection among the words. And it means nonsense.

The following constituents (parts) may be called the main grammatical signals (markers):

1. 
   Affixation (inflexion)
   
2. 
   Function(al) words
   
3. 
   Word order
   
4. 
   Intonation
   
5. 
   Suppletive forms
   

6. 
   The change of the place of the stress in the word
   
7. 
   Repetition of words
   

These signals are universal. Concrete languages select them to characterize their grammatical system. For instance, the English Grammar mainly chooses affixation (inflections), the Chinese language chooses word order and intonation. The Uzbek language chooses function(al) words and affixation.

As a special science Grammar has some periods of development, which we distinguish traditionally. There is no accepted periodization of the history of the English grammar, but we shall roughly divide it into 3 periods. This division is taken according to the general aims of grammar which appeared within these 3 periods.
The first is the age of pre-scientific grammar which began at end of 16th century and lasted till 17^th. The first grammar is the early reformative grammar of English, beginning with the Brief Grammar of English (1585). The representatives of this period are the Greek philosopher Aristotle, Protogor and others. They distinguished primary grammatical categories (parts of speech). Later on Stoicks separated some secondary grammatical categories, such as gender and case of nouns.
The second period is bound with the appearance of the universal grammar of Porr Royal appeared in the 17^th century in France the main point of this grammar was that the language structure was treated as a system. By the middle of the 18^th century when many of the grammatical phenomena of the English language had been described, the early English grammar gave way to a new kind of grammar, that is a normative grammar. It is the only kind of grammar used in practical teaching of the English language. This was the first English grammar which based on the Latin grammar.
By the end of the 19^th century Scientific Grammar appeared. In contrast with normative grammar, scientific grammar is both descriptive and explanatory, for ex., Henry Sweet's grammar. A number of modern linguists say that this type of grammar is the most fruitful approach to the description of grammatical system of the English language

1. General or Universal Grammar, which studies general rules of grammatical system of the language. The task of such a grammar is to find the most general structures of patterns which are common to majority of languages, for ex., Universal grammar of Purr Royal.

2. Philosophical Grammar, which deals with the grammatical and philosophical or logical categories and finds connections between language and mind. The example of such a grammar is the theory of Danish scholar Otto Yespersen.
3.Historical grammar, which studies the development of the grammatical structure of the language in the course of time, for ex., in Old English there were 3 genders of nouns.
4. Practical or normative grammar. It is a book of rules which aims to teach the art of correct writing and speaking.
5. Theoretical grammar studies the general theory and gives the analysis of the grammatical structure.

6.