The root communicates the basic meaning of the verb, e.g. ك-ت-ب k-t-b 'write', ق-ر-ء q-r-ʾ 'read', ء-ك-ل ʾ-k-l '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.
Arabic grammarians typically use the root ف-ع-ل f-ʿ-l 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.
A total of 13 forms exist for each of the two stems, specifying person (first, second or third); number (singular, dual or plural); and gender (masculine or feminine).
The imperative exists only in the second person and is distinguished from the jussive by the lack of the normal second-person prefix ـت ta-/tu-.
The usage of Arabic tenses is as follows: In all but Form I, there is only one possible shape for each of the past and non-past stems for a given root.
In less formal Arabic and in spoken dialects, the subjunctive mood is used as the only imperfective tense (subjunctivism) and the final ḥarakah vowel is not pronounced.
The imperative (صِيغَة اَلْأَمْر ṣīghat al-amr) (positive, only 2nd person) is formed by dropping the verbal prefix (ت-) from the imperfective jussive stem, e.g. قَدِّم qaddim 'present!'.
If the result starts with two consonants followed by a vowel (a or i), an elidible alif (ا) is added to the beginning of the word, usually pronounced as "i", e.g. اِغْسِلْ ighsil 'wash!'
In these verbs a non-elidible alif ا pronounced as a- is always prefixed to the imperfect jussive form, e.g. أرسل arsil "send!
For example: Thus, the active and passive forms are spelled identically in Arabic; only their vowel markings differ.
As shown by the English examples, its meaning refers both to the act of doing something and (by frequent semantic extension) to its result.
), is used to specify grammatical concepts such as causative, intensive, reciprocal, passive or reflexive, and involves varying the stem form.
Examples of the different forms of a sound verb (i.e. with no root weaknesses), from the root ك-ت-ب k-t-b 'write' (using ح-م-ر ḥ-m-r 'red' for Form IX, which is limited to colors and physical defects): The main types of weakness are as follows: In Arabic the grammatical person and number as well as the mood are designated by a variety of prefixes and suffixes.
The following table shows the paradigm of a regular sound Form I verb, kataba (كتب) 'to write'.
Forms katabtu and katabta (and sometimes even katabti) can be abbreviated to katabt in spoken Arabic and in pausa, making them also sound the same.
The full non-past stem رْمِيْـ rmiy- appears as رْمِيـ rmī- when not before a vowel; this is an automatic alternation in Classical Arabic.
There are the same irregular endings in the same places, and again two stems in each of the past and non-past tenses, with the same stems used in the same places: The Arabic spelling has the following rules: The following shows a paradigm of a typical Form I defective (third-weak) verb نَسِيَ (يَنْسَ) nasiya (yansā) (root: ن-س-ي) 'to forget', parallel to verbs of the فَعِلَ (يَفْعَلُ) faʿila (yafʿalu) type.
The endings are for the most part identical to those of strong verbs, but there are two stems (a regular and a modified) in each of the past and non-past.
No initial vowel is needed in most of the imperative forms because the modified non-past stem does not begin with two consonants.
As a result, for the doubled verbs in particular, there is a tendency to harmonize these forms by adding a vowel to the jussives, usually ـَ a, sometimes ـِ i.
Forms IX and XI are used only with adjectival roots referring to colors and physical defects (e.g. "red", "blue", "blind", "deaf", etc.
The construction of a given augmentation is normally indicated using the dummy root f–ʿ–l (ف–ع–ل), based on the verb faʿala 'to do'.
The system of identifying verb augmentations by Roman numerals is an invention by Western scholars.
The consonant cluster ضط ḍṭ, as in اضطرّ iḍṭarra 'compel, force', is unexpected given modern pronunciation, having a voiced stop next to a voiceless one; this reflects the fact that ط ṭ was formerly pronounced voiced, and ض ḍ was pronounced as the emphatic equivalent not of د d but of an unusual lateral sound.
The active and passive participles of derived defective verbs consistently are of the -in and -an declensions, respectively.
Heywood and Nahmad list one such verb, iʿmāya 'be/become blind', which does not follow the expected form اعميّ *iʿmayya.
The initial w also drops out in the common Form I verbal noun علة ʿilah (e.g. صلة ṣilah 'arrival, link' from وصلة waṣalah 'arrive').
This affects the following forms: In addition, any place where a hamzat al-waṣl (elidable hamzah) occurs will optionally undergo this transformation.