Concept
Arabic verbs (فِعْل ALA; () أَفْعَال ALA), like the verbs in other Semitic languages, and the entire vocabulary in those languages, are based on a set of two to five (but usually three) consonants called a root (triliteral or quadriliteral according to the number of consonants). The root communicates the basic meaning of the verb, e.g. ك-ت-ب ALA 'write', ق-ر-ء ALA 'read', ء-ك-ل ALA 'eat'. Changes to the vowels in between the consonants, along with prefixes or suffixes, specify grammatical functions such as person, gender, number, tense, mood, and voice. Various categories are marked on verbs: Three tenses (present, past; future tense is indicated by the prefix sa- or the particle sawfa and the present tense). Two voices (active, passive) Two genders (masculine, feminine) Three persons (first, second, third) Three numbers (singular, dual, plural) Six moods in the non-past only (indicative, subjunctive, jussive, imperative, and short and long energetics) Nineteen forms, the derivational systems indicating derivative concepts such as intensive, causative, reciprocal, reflexive, frequentative etc. For each form, there is also an active and a passive participle (both adjectives, declined through the full paradigm of gender, number, case and state) and a verbal noun (declined for case; also, when lexicalized, may be declined for number). Weakness is an inherent property of a given verb determined by the particular consonants of the verb root (corresponding to a verb conjugation in Classical Latin and other European languages), with five main types of weakness and two or three subtypes of each type. Arabic grammarians typically use the root ف-ع-ل ALA to indicate the particular shape of any given element of a verbal paradigm. As an example, the form يتكاتب (root: ك-ت-ب) yutakātabu 'he is corresponded (with)' would be listed generically as يتفاعل yutafāʿalu (yuta1ā2a3u), specifying the generic shape of a strong Form VI passive verb, third-person masculine singular present indicative.