Ўзбекистон республикаси олий ва ўрта махсус таълим вазирлиги cамарқанд давлат чет тиллар институти инглиз тили грамматикаси ва тарихи кафедраси

Types of Sentences according to the Aim of the Speaker
The declarative sentences: This type of sentence may be called basic, when compared with other types of sentences because all other types of sentences are the result of transformation of kernel sentences which are affirmative in their origin (kernel sentences).

• 
  they convey some statement. Maybe because of this fact these sentences are called declarative.
  
• 
  they usually have the falling an intonation
  
• 
  usually they have regular order of words with no inversion.
  

Interrogative Sentences
Interrogative sentences differ from the declarative or interrogative ones by some their specific features.
There are two structural types of interrogative sentences in Modern English - general questions (yes- or no- questions) and special (or wh-) questions. Both of them are characterized by having partial inversions:
Are we staying here?
Where are we staying?
Besides, the first one has a special (rising) intonation pattern. The second one (wh-question) has interrogative words. But the intonation pattern of wh-questions is identical with that of the affirmative sentences.
And it is important to point out that the interrogative sentences require answers (if they are not rhetorical ones).
Exclamatory Sentences
The peculiar features of these sentences are:

1. 
   exclamatory sentences usually express some sort of emotion, feeling or the spirit of the person who pronounces it;
   
2. 
   in their structure they have such introductory words as what and how: Ex. What a lovely night! How beautiful it is here!
   
3. 
   they are always in the declarative form;
   
4. 
   there’s usually no inversion;
   
5. 
   they are pronounced with a falling intonation;
   

Imperative Sentences
The imperative sentences are opposed to non-imperative ones because.

1. 
   In imperative sentences the predicate is used in only one form-in the imperative one, while in non-imperative sentences predicate may be used in any form except the imperative.
   
2. 
   In imperative sentences no modal verb is used.
   
3. 
   The imperative sentences are most often directed to the second person.
   
4. 
   The subject of the imperative sentences are almost always represented by the zero alternant of you, that is, elliptically.
   
5. 
   The imperative sentences urge the listener to perform an action or verbal response.
   

The above said is quite sufficient to characterize the structure of imperative sentences to be specific and distinct from that of the structure of non-imperative sentences.