The roots of verbs and most nouns in the Semitic languages are characterized as a sequence of consonants or "radicals" (hence also the term consonantal root). Such abstract consonantal roots are used in the derivation of actual words by adding the vowels and non-root consonants (or "transfixes") which go with a particular morphological category around the root consonants, in an appropriate way, generally following specific patterns. It is a peculiarity of Semitic linguistics that a large majority of these consonantal roots are triliterals (although there are number of quadriliterals, and in some languages also biliterals).
A triliteral or triconsonantal root (Arabic: جذر ثلاثي, ǧaḏr ṯalāṯī) is a root containing a sequence of three consonants.
The following are some of the forms which can be derived from the triconsonantal root k-t-b (general overall meaning "to write") in Hebrew and Arabic:
|Semitological abbreviation||Hebrew name||Arabic name||Morphological category||Hebrew Form||Arabic form||Approximate translation|
|G verb stem||Qal||fa‘ala |
|3rd. masc. sing perfect||katabh כתב||kataba كتب||"he wrote"|
|1st. plur. perfect||katabhnu כתבנו||katabnā كتبنا||"we wrote"|
|3rd. masc. sing. imperfect||yikhtobh יכתוב||yaktubu يكتب||"he writes, will write"|
|1st. plur. imperfect||nikhtobh נכתוב||naktubu نكتب||"we write, will write"|
|masc. sing. active participle||kotebh כותב||kātib كاتب||"writer"|
|Š verb stem||Hiph‘il||af‘ala |
|3rd. masc. sing perfect||hikhtibh הכתיב||’aktaba أكتب||"he dictated"|
|3rd. masc. sing. imperfect||yakhtibh יכתיב||yuktibu يكتب||"he dictates, will dictate"|
|Št(D) verb stem||Hitpa‘‘el||istaf‘ala |
|3rd. masc. sing perfect||hitkattebh התכתב||istaktaba استكتب||"he corresponded" (Hebrew), "he asked (someone) to write (something), had a copy made" (Arabic)|
|3rd. masc. sing. imperfect||yitkattebh יתכתב||yastaktibu يستكتب||(imperfect of above)|
|Noun with m- prefix and original short vowels:||maf‘al |
|singular||mikhtabh מכתב||maktab مكتب||"letter" (Hebrew), "office" (Arabic)|
- Note: The Hebrew fricatives transcribed as "kh" and "bh" above are single phonetic sounds, which can also be transcribed in a number of other ways, such as "ch" and "v" (Eastern-European influenced) or [x] and [v] (IPA). They are transcribed "kh" and "bh" on this page to retain the connection with the pure consonantal root k-t-b.
In Hebrew grammatical terminology, the word binyan (Hebrew בנין, plural בינינים binyanim) is used to refer to a verb stem or overall verb derivation pattern, while the word Mishqal (or Mishkal) is used to refer to a noun derivation pattern, and these words have gained some use in English-language linguistic terminology. The Arabic terms, called وزن wazn, (plural أوزان, ’awzān) for the pattern and جذر ǧaḏr (plural جذور, ǧuḏūr) for the root have not gained the same currency as the Hebrew equivalents, and Western grammarians continue to use "stem"/"form"/"pattern" for the former and "root" for the latter (though "form" and "pattern" are literal translations of wazn, and "root" is a literal translation of ǧaḏr).
Biliteral origin of (some) triliteral roots
Ghil'ad Zuckermann says, "Note that although most roots in Hebrew seem to be tri-radical, many of them were originally bi-radical, cf. the relation between גזז √ g-z-z ‘shear’, גזמ √ g-z-m ‘prune’ and גזר√ g-z-r ‘cut’, as well as between פרז√ p-r-z ‘divide a city’, פרט √ p-r-ţ ‘give change’ and פרע √ p-r-‘ ‘pay a debt’." Zuckermann analyses the Hebrew root שקפ √ sh-q-p "look out/through" as deriving from קפ√ q-p "bend, arch, lean towards" (cf. קפח√ q-p-ħ, קפה√ q-p-h, קפא √ q-p-' and קפי √ q-p-y "arch, bend"), fitted into the shaé verb-pattern. "This verb-pattern is usually causative, cf. שטפ√ sh-ţ-p ‘wash, rinse, make wet’, from טפ √ ţ-p ‘wet’, as well as שלכ √ sh-l-k ‘cast off, throw down, cause to go’, from לכ √ l-k ‘go’".
A quadriliteral is a consonantal root containing a sequence of four consonants (instead of three consonants, as is more often the case). A quadriliteral form is a word derived from such a four-consonant root. For example, the abstract quadriliteral root t-r-g-m / t-r-j-m gives rise to the verb forms תרגם tirgem in Hebrew and ترجم tarjama in Arabic, meaning "he translated". In some cases, a quadriliteral root is actually a reduplication of a two-consonant sequence. So in Hebrew דגדג digdeg means "he tickled", and in Arabic زلزال zilzāl means "earthquake".
Generally, only a subset of the verb derivations formed from triliteral roots are allowed with quadriliteral roots. For example, in Hebrew the Pi``el, Pu``al, and Hitpa``el, and in Arabic forms similar to the stem II and stem V forms of triliteral roots.
Traditionally in the Semitic languages, forms with more than four basic consonants (i.e. consonants not introduced by morphological inflection or derivation) were occasionally found in nouns — mainly loanwords from other languages — but never in verbs. However, in modern Israeli Hebrew, syllables are allowed to begin with a sequence of two consonants (a relaxation of the situation in early Semitic, where only one consonant was allowed), and this has opened the door to apparent five root-consonant forms, such as טלגרף tilgref "he telegraphed". But, -lgr- always appears as an indivisible cluster in the derivation of this verb, so that these five root-consonant forms do not display any fundamentally different morphological patterns from four root-consonant forms (and the hypothetical term "quinqueliteral" would be misleading if it implied otherwise).
- apophony vs. transfixation (root-and-pattern)
- Arabic grammar
- broken plural
- nonconcatenative morphology
- Phono-semantic matching
- Proto-Indo-European root