The main parts of the sentence
The order of the parts of the simple sentence
Agreement of the verbal and nominal members in number
Complex sentences

The main parts of the sentence
(Extended and unextended simple sentences)
Simple unextended sentences contain only main parts of sentences: a subject, a verb predicate, a direct object and an indirect object.
If a simple semtence includes any other word, it is a simple extended sentence.

E.g.: Ninom Lelas c'erili misc'era  - Nino wrote a letter to Lela - this is a simple unextended sentence.
Nino sk'amze zis - Nino is sitting on the chair - this is a simple extended sentence because the phrase on the chair is not a main part of the sentence.

The order of the parts of the simple sentence
Word order is relatively free in Georgian. Relations between members of the sentence are expressed not by the order of the parts of the sentence (as in Swedish or English: Dato hit Vano or Vano hit Dato mean different things) but by the case and person marking in Georgian. That is why word order changes are connected with a logical emphasis but not with the change of the grammatical functions of the members. The most neutral word order in a simple sentence is the following:
subject - indirect object - direct object - verb-predicate:
 

Nino wrote a letter to the friend

Subject	Indirect object	Direct object	Verb-predicate
ნინომ	მეგობარს	წერილი	მისწერა
Ninom	megobars	c'erili	misc'era
Nino	to friend	letter	wrote

Another order is also allowed:
 

Nino wrote a letter to the friend

Subject	Direct object	Verb-predicate	Indirect object
ნინომ	წერილი	მისწერა	მეგობარს
Ninom	c'erili	misc'era	megobars
Nino	letter	wrote	to friend

 

Nino wrote a letter to the friend

Indirect object	Direct object	Verb-predicate	Subject
მეგობარს	წერილი	მისწერა	ნინომ
megobars	c'erili	misc'era	Ninom
to friend	letter	wrote	Nino

etc.
 

Agreement of the verbal and nominal members in number
When the number is expressed by a numeral, both the determined word (ქალი kali) and the verb-predicate remain in the singular:
 
 

ორი ქალი მიდის. ori kali midis. two woman goes. Two women go.

But:
 

ქალები მიდიან.  kal-eb-i midian.  woman-Plur-Nom go. Women go.

When an inanimate subject is plural, the verb-predicate remains in the singular:
 

სახლის წინ ხეები დგას. saxl-is c'in xe-eb-i dgas. house-Gen. front tree-Plur-Nom. stands/is standing. There are trees in front of the house.

But:
 
 

სახლის წინ ბავშვები დგანან. saxl-is c'in bavshv-eb-i dganan. house-Gen. front child-Plur-Nom. stand/are standing. The children are standing in front of the house.

More information:

Complex sentences