In the Georgian grammatical tradition,  two main classifications have been proposed by Arnold Chikobava and Ak'ak'i Shanidze. Chikobava and his followers consider the transitive/intransitive and dynamic/stative distinctions to be the main classificatory morphological category of the Georgian verb.  In the school of Ak'ak'i Shanidze, the criterion is voice. Morphological patterns of verbs, types of conjugation, as well as syntactical constructions, are differentiated according to the voice.

Main morphological models of the Georgian verbs
The symbol C indicates a consonant and the symbol V indicates a vowel in the table below
The segment VC is either a thematic marker or a vowel altrenating segment.

Transitive and intransitive verbs

Voice

• Definition
• Derivation
• Active voice
• Passive voice
• Middle voice

A transitive verb requires a direct object to make the meaning complete, e. g.: I saw him.
An intransitive verb does not require a direct object. It only characterises the subject: I slept.
These notions are defined by formal criteria in Georgian.

Formal definition of transitivity

• Verbs which have a direct object are transitive verbs.
• Verbs which have no direct object are intransitive verbs.

(All active verbs in Georgian are transitive but not all transitives are active).

Semantic definition of a direct and an indirect object

• The direct object is that part of the sentence to which the action of the subject  immediately refers.
• The indirect object is that part of the sentence which is indirectly affected (indirectly from the position of the subject); e.g.: She gave me a book. A book is a direct object (touched by a subject) and me is an indirect object (not touched by a subject).

Formal definition of a direct and an indirect object

• A direct object is marked by the dative case in the tenses of series I and by the nominative case in the tenses of Series II and III. 
  
• An indirect object is marked by the dative case in both the first and the second series.

Definition

Voice describes the relations between a grammatical subject and an action expressed by the verb. These relations can be expressed in three ways in Georgian:

1. Active voice  (Verb Class I)
A grammatical subject acts and its action is directed to the direct object; e. g.:
ქალ-ი წყალ-ს ადუღებს
kal-i c'q'al-s adughebs (A woman-Nom. water-Dat. is boiling)
A woman is boiling the water.

2. Passive voice (Verb Classes II and IV)
A grammatical subject is acted upon (like the direct object in the active voice) but the real acting person is not shown by the verb form; e. g.:
წყალი დუღდება
c'q'ali dughdeba
The water is being boiled.

3. Middle voice (Verb Class III and one group of Verb Class IV)
A grammatical subject is represented by the verb form as a subject which is not acted upon but is acting itself though this "acting" subject has no direct object to which the action of the subject would have referred; e. g.:
წყალი დუღს
c'q'ali  dughs
The water is boiling.

The form of middle voice verbs is like that of active verbs, while the function is like that of passive verbs.

In conjugation, one group of the so-called middle voice verbs follow the patterns of active verbs and are known as the middle-active verbs.  Another group of middles follow the patterns of passive verbs and are known as the middle-passive verbs.

N o t e:
Not all verbs have forms of all three voices. Active-passive opposition is more common than active-passive-middle.

One group of verbs have only one form in this respect. They are called the verbs without voice since there is no opposition to other forms.

• Active voice
• Passive voice
• Middle voice

All active voice verbs have one shared formal feature: they end in the person marker -s in the third person singular, the present tense, and, at the same time, they form the future tense by adding the preverb to the present tense; e. g.:
წერ-ს c'er-s he/she writes (// he/she is writing)
და-წერ-ს da-c'er-s he/she will write (// he/she will be writing)
The active voice verbs form the conjugation type 1 (it is the same as Class I verbs. They usually have syntactic pattern B).

More detailed analysis follows below:

In the present form the active voice pattern is represented either as a simple theme (monothematic verbs) or a complicated theme (bithematic verbs) determined by the thematic suffix. One group of monothematic verbs undergo vowel alteration.

1. A simple theme (without thematic suffix) (monothematic verbs): წერ-ს c'er-s (he/she) is writing, ჭამ-ს ch'am-s  (he/she) is eating, ბან-ს ban-s  (he/she) is washing (only about animate object, if the object is inanimate then the other verb რეცხ-ავ-ს recx-av-s is used) etc.

2. A complicated theme with the thematic suffix (bithematic verbs)
The most common used thematic suffixes are -i, -av, -am, -eb, -ob:

• - ------ -i: თლ-ი-ს tl-i-s (he/she) is peeling
• - ----- -av: მალ-ავ-ს mal-av-s (he/she) is hiding, concealing smth.
• - ----- -am: დგ-ამ-ს dg-am-s (he/she) is putting (to stand) smth.
• a- ----- -eb: ა-კეთ-ებ-ს a-k'et-eb-s (he/she) is doing/making smth.,
• a- ------ -ob: ა-თბ-ობ-ს a-tb-ob-s (he/she) is warming smth.

Thus, three types of active voice verbs are identifiable:
 

All active verbs undergo inversion (exchange of functions between the subject and object person markers and case marking) in the third series.

A part of active voice verbs is derived from the passive and middle voice verbs; see Transitivity and contact.

Click here to see more particularly analysed example.

Click here to see more particularly analysed example.

Passive voice verbs are divided into two big groups: dynamic passive verbs (Class II) and stative passive verbs (one subgroup of Class IV).
Some groups of the so-called passive verbs can express the function of active verbs.
The term passive voice implies intransitivity rather than the same sense as the term passive voice in, for example, English.

All dynamic passive voice verbs have one shared formal feature: they end in the marker -eb-a in the third person singular, the present tense, and, at the same time, they form the future tense by adding the preverb to the present tense; e. g.:
თბ-ებ-ა tb-eb-a he/she warms herself/himself / s/he gets warmed
გა-თბ-ებ-ა ga-tb-eb-a he/she will warm herself/himself s/he will get warmed

More detailed analysis follows below:
 

Dynamic passive verbs  (Verb Class II)
Dynamic passive verbs make up Class II. They make three groups within this type:

1. Passive formed by prefix (Prefixal passive):

• Passive formed by prefix i-:ი-წერ-ებ-ა i-c'er-eb-a it is being written, იხატება i-xat'eb'a It is being painted. The corresponding active  is a primary form relative to the passive and is usually formed without a vowel prefix: წერ-ს c'er-s He is writing it, ხატ-ავ-ს xat'-av-'s He is painting it.
  
• Passive formed by prefix e-: ე-წერ-ებ-ა e-c'er-eb-a it is being written for smb. ე-ხატ-ებ-ა e-xat'eb'a It is being painted for smb. The corresponding active is a primary form relative to the passive and is usually has the vowel prefix უ- u-: უ-წერ-ს u-c'er-s He is writing it for somebody.
  უ-ხატ-ავ-ს u-xat'-av-'s He is painting it for smb. (the ability of verb to express who is intended receiver of the action result is called version).

3. Passive "without marker" (Markerless passive): თბ-ებ-ა tb-eb-a s/he/it is warming him/her/itself, is being warmed. The corresponding active is a secondary form relative to the passive and is usually formed from the passive by means of a vowel prefix and a thematic suffix: ა-თბ-ობ-ს a-tb-ob-s He is warming smth. They are usually non-syllabic (but not monoconsonantal) roots: tb--eb-a, qr-eb-a, shr-eb-a, etc.
If the active voice takes a vowel prefix u-, the corresponding markerless passive also takes the prefix u-, e.g.:  უ-თბ-ობ-ს u-tb-ob-s He is warming smth for somebody. უ-თბ-ებ-ა u-tb-eb-a It is being warmed for somebody.

All dynamic passive verbs (among them "markerless passive") have one common feature:  in the present tense, in the third subject person (in singular), all of them have the ending -eb-a, where -eb is a thematic suffix, and -a is the third subject person marker.  The verbs ending in the suffixes -ev-a and -ob-a also belong to this type:

This type, so-called passive voice verbs, often expresses active action, e.g.

Actually, it would have been more appropriate to call them the -eb-i verbs, according to their form.

Stative passive verbs  (verb class IV)

These verbs belong to Clss IV, the subgroup with the ending i-var/i-a.
Stative passive verbs end in -ia in the present (the third subject person in singular). They form the first and the second subject person forms by means of the auxiliary verb to be:

Some transitive verbs can have two corresponding passive forms: dynamic passive and stative passive; e. g.:

The middle-active voice verbs follow the active verbs syntactic pattern: their subject is marked by the ergative case in the second series and by the dative case in the third series. Inversion (exchange of functions between the subject and the object persons markers) occurs in tenses of the  third series.  

Another group of the middle voice verbs follows the passive verbs pattern: their subject is marked by the nominative case in all three series. Inversion does not occur. Such middle-voice verbs are called middle-passive verbs (two subgroups of Class IV).

In some groups of the so-called middle-passive verbs, the subject is marked by the dative in all three series and inversion occurs in all three series. The subject of such verbs is either an experiencer or a possessor subject: მიყვარს miq'vars I love him/her/it, მძულს  mdzuls I hate him/her/it, etc. They have the inversive syntactic structure (Pattern C).
Non-inversive, regular Class III verbs are presented below:

Middle-active verbs (VERB CLASS III)