Discover

In the terminology used to discuss the grammar of the Semitic languages, 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 ''zalzāl'' 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).