Correspondences between sounds and meanings in words and word elements provide a basis for considering the Kartvelian languages as being closely related and descended from a common ancestral language (a protolanguage).
The sound system of the Kartvelian languages is relatively uniform, with only the vowel systems exhibiting considerable differences. Apart from the five cardinal vowels a, e, i, o, u, which exist in all the Kartvelian languages, the Svan dialects show several additional vowels: the front (or palatalized) vowels, ä, ö, ü, and a high central vowel, ə (as the a in English “sofa”). All these vowels also have distinct lengthened counterparts, thus giving a total of 18 distinctive vowels in some dialects of Svan. Vowel length is not distinctive in the other Kartvelian languages.
Within the Kartvelian consonant system the stops and affricates have voiced, voiceless, and glottalized varieties. (Stops are produced by complete but momentary stoppage of the breath stream some place in the vocal tract; affricates are sounds begun as stops but released with local friction, such as the ch sounds in “church.” Voiced sounds are made with vibrating vocal cords; in voiceless sounds, the vocal cords do not vibrate; glottalized consonants, indicated in phonetic transcription by dots below or above certain letters, are pronounced with an accompanying closure of the glottis [the space between the vocal cords].) Fricative sounds (e.g., s, z, v), which are characterized by local friction, have only voiced and voiceless types.
Although most word roots begin with one or two consonants, instances of long consonant clusters in word-initial position occur quite frequently, especially in Georgian, in which such clusters may comprise up to six consonants—e.g., Georgian prckvna “peeling,” msxverṗli “sacrifice.”
The Kartvelian languages exhibit a developed system of word inflection (e.g., the use of endings, such as English “dish, dishes” or “walk, walks, walked”) and derivation (word formation). Derivation is characterized by compounding, the combination of words to form new words, as well as by affixation, the addition of prefixes and suffixes—e.g., Georgian kartvel-i “Georgian,” sa-kartvel-o “Georgia”; Mingrelian žir-i “two,” ma-žir-a “second.”
The verb system distinguishes the categories of person, number (singular and plural, with differentiation of inclusive and exclusive plural in Svan), tense, aspect, mood, voice, causative, and version (the latter defines the subject–object relations). These categories are expressed mainly by the use of prefixes and suffixes, as well as by internal inflection (changes within the verb stem), which is frequently a redundant grammatical feature.
The system of verb conjugation in Kartvelian languages is multipersonal; that is, the verb forms can indicate the person of the subject (the agent) and of the direct or indirect object by the use of special prefixes. (The subject of the third person is marked by endings in Georgian and Mingrelo-Laz and by a lack of ending in Svan.) An example is Georgian m-c̣er-s “he writes to me,” m-xaṭav-s “he paints me,” in which m denotes the first person as object and s marks the third person as subject. The finite verb forms fall into three series of tenses: the present tense, the aorist (indicating occurrence, usually past, without reference to completion, duration, or repetition), and the perfect or resultative (denoting an action in the past not witnessed by the speaker).
There is a developed system of preverbs, elements preceding the verb stem and attached to it, with local meaning indicating location of the action in space, as well as its direction (especially in Mingrelian and Laz). Simple preverbs are combined into complex ones. The preverbs are also used to mark the aspect (nature of the action indicated by the verb, with reference to its beginning, duration, completion), which is used for the formation of future and aorist forms—e.g., Georgian c̣er-s “he writes” versus da-c̣er-s “he will write” and da-c̣er-a “he wrote.”
The nominal (noun, pronoun, adjective) system is distinguished by less structural complexity than the verb system and has cases varying in number from 6 to 11. The six cases common to all the Kartvelian languages are: nominative, marking subject of the intransitive verb; ergative (see below), modified in Mingrelian and Laz; genitive, marking possession; dative, marking indirect objects; ablative–instrumental, expressing relations of separation and source and means or agency; and adverbial, expressing goal of the action—e.g., “to make it.” There are also some secondary local cases (in New Georgian, Mingrelian) that indicate location and direction toward the object as well as from the object (rendered in English by such prepositions as “in,” “on,” “to,” “from,” and so on). The nominal system does not distinguish gender, which is absent even in pronouns, and there are no special articles (such as English “a,” “the”).
A basic feature of Kartvelian syntax is the ergative construction of the sentence. The subject of a transitive verb (the agent) is marked by a special agentive, or ergative, case, while the case of the direct object is the same as that of the subject with intransitive verbs, traditionally called the nominative case—e.g., Georgian ḳac-i (nominative) midis and Svan māre (nominative) esɤri, “the, or a, man goes” but Georgian ḳac-ma (ergative) moḳla datv-i (nominative) and Svan mārēĩ (ergative) adgär däšdw (nominative) “the, or a, man killed the, or a, bear.” A specific feature of the Georgian and Svan ergative construction is its restriction to the aorist series (i.e., that showing simply occurrence). In the present-tense series the subject (agent) of transitive as well as intransitive verbs is put into the same nominative case, and the direct object is in the dative—e.g., Georgian ḳac-ma (ergative) moḳla datv-i (nominative) “the man killed a bear” (aorist), but ḳac-i (nominative) ḳlavs datv-s (dative) “the, or a, man kills the, or a, bear” (present tense). In Mingrelian the ergative case with the formative (suffix) -k extends in the aorist series to the constructions with intransitive verbs and results in a formation of two distinct subject cases. In Laz, conversely, the case with the formative -k extends to the constructions with transitive verbs in the present-tense series.