Tense

There are three tenses in Arabic: the past tense (اَلْمَاضِي al-māḍī), the present tense (اَلْمُضَارِع al-muḍāriʿ) and the future tense. The future tense in Classical Arabic is formed by adding either the prefix ‏سَـ‎ sa- or the separate word ‏سَوْفَ‎ sawfa onto the beginning of the present tense verb, e.g. سَيَكْتُبُ sa-yaktubu or سَوْفَ يَكْتُبُ sawfa yaktubu 'he will write'.

In some contexts, the tenses represent aspectual distinctions rather than tense distinctions. The usage of Arabic tenses is as follows:

• The past tense often (but not always) specifically has the meaning of a past perfective, i.e. it expresses the concept of 'he did' as opposed to 'he was doing'. The latter can be expressed using the combination of the past tense of the verb كَانَ kāna 'to be' with the present tense or active participle, e.g. كَانَ يَكْتُبُ kāna yaktubu or كَانَ كَاتِبٌ kāna kātibun 'he was writing'. There are some special verbs known as "compound verbs" that can express many grammatical aspects such as Inchoative, Durative etc., for example بَدَأ يُلْفِتُ النَظرَ badaʾa yulfitu al-naẓara means "It started to attract attention" which badaʾa conveys the meaning of "to start doing something (in the past)"
• The two tenses can be used to express relative tense (or in an alternative view, grammatical aspect) when following other verbs in a serial verb construction. In such a construction, the present tense indicates time simultaneous with the main verb, while the past tense indicates time prior to the main verb. (Or alternatively, the present tense indicates the imperfective aspect while the past tense indicates the perfective aspect.)

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 Form I, however, different verbs have different shapes. Examples:

• كَتَبَ يَكْتُبُ kataba yaktubu 'write'
• كَسِبَ يَكْسِبُ kasaba yaksibu 'earn'
• قَرَأَ يَقْرَأُ qaraʾa yaqraʾu 'read'
• قَدِمَ يَقْدَمُ qadima yaqdamu 'turn'
• كَبُرَ يَكْبُرُ kabura yakburu 'become big, grow up'

Notice that the second vowel can be any of a i u in both past and non-past stems. The vowel a occurs in most past stems, while i occurs in some (especially intransitive) and u occurs only in a few stative verbs (i.e. whose meaning is 'be X' or 'become X' where X is an adjective). The most common patterns are:

• past: a; non-past: u or i
• past: a, non-past: a (when the second or third root consonant is a "guttural," i.e. one of ʾ ʿ h ḥ)
• past: i; non-past: a
• past: u; non-past: u

Mood

There are three moods (حَالَات ḥālāt, a word that also means "cases"; sg. ‏حَالَة‎ ḥālah), whose forms are derived from the imperfective stem: the indicative mood (‏مَرْفُوع‎ marfūʿ), usually ending in u; the subjunctive (‏مَنْصُوب‎ manṣūb), usually ending in a; and the jussive (‏مَجْزُوم‎ majzūm), with no ending. 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!' or اِفْعَل ifʿal 'do!' if the present form vowel is u, then the alif is also pronounced as u, e.g. أُكْتُب uktub 'write!'. Negative imperatives are formed from the jussive.

The exception to the above rule is the form (or stem) IV verbs. In these verbs a non-elidible alif ا pronounced as a- is always prefixed to the imperfect jussive form, e.g. أرسل arsil "send!", أضف ^[1]aḍif 'add!'.

The subjunctive is used in subordinate clauses after certain conjunctions. The jussive is used in negation, in negative imperatives, and in the hortative la+jussive. For example: 2. sg. m.:

• imperfect indicative تفعلُ tafʿalu 'you are doing'
• subjunctive أن تفعلَ an tafʿala 'that you do'
• jussive لا تفعلْ lā tafʿal its meaning is dependent upon the prefix which attaches to it; in this case, it means 'may you do not do!'
• short energetic تفعلنْ tafʿalan its meaning is dependent upon the prefix which attaches to it; if the prefix is "la" it means 'you should do'
• long energetic تفعلنَّ tafʿalanna it has more emphasis than the short energetic, its meaning is dependent upon the prefix which attaches to it; if the prefix is "la" it means 'you must do'
• imperative افعل ifʿal 'do!'.

Voice

Arabic has two verbal voices (صِيغَات ṣīghāt "forms", sg. صِيغَة ṣīghah), active (صِيغَة اَلْمَعْلُوم ṣīghat al-maʿlūm), and passive (صِيغَة اَلْمَجْهُول ṣīghat al-majhūl). The passive voice is expressed by a change in vocalization. For example:

• active فَعَلَ faʿala 'he did', يَفْعَلُ yafʿalu 'he is doing'
• passive فُعِلَ fuʿila 'it was done', يُفْعَلُ yufʿalu 'it is being done'

Thus, the active and passive forms are spelled identically in Arabic; only their vowel markings differ. There are some exceptions to this in the case of weak roots.

Participle

Every verb has a corresponding active participle, and most have passive participles. E.g. معلم muʿallim 'teacher' is the active participle to stem II. of the root ع-ل-م ʿ-l-m ('know').

• The active participle to Stem I is فاعل fāʿil, and the passive participle is مفعول mafʿūl.
• Stems II–X take prefix مـ mu- and nominal endings for both the participles, active and passive. The difference between the two participles is only in the vowel between the last two root letters, which is -i- for active and -a- for passive (e.g. II. active مفعِّل mu-faʿʿil, and passive مفعَّل mu-faʿʿal).

Verbal noun (maṣdar)

In addition to a participle, there is a verbal noun (in Arabic, مَصْدَر maṣdar, pl. مَصَادِر maṣādir, literally meaning 'source'), sometimes called a gerund, which is similar to English gerunds and verb-derived nouns of various sorts (e.g. "running" and "a run" from "to run"; "objection" from "to object"). As shown by the English examples, its meaning refers both to the act of doing something and (by frequent semantic extension) to its result. One of its syntactic functions is as a verbal complement of another verb, and this usage it corresponds to the English gerund or infinitive (He prevented me from running or He began to run).

• verbal noun formation to stem I is irregular.
• the verbal noun to stem II is تفعيل tafʿīl. For example: تحضير taḥḍīr 'preparation' is the verbal noun to stem II. of ح-ض-ر ḥ-ḍ-r ('to be present').
• stem III often forms its verbal noun with the feminine form of the passive participle, so for ساعد sāʿada, 'he helped', produces the verbal noun مساعدة musāʿadah. There are also some verbal nouns of the form فعال fiʿāl: جاهد jāhada, 'he strove', yields jihād جهاد 'striving' (for a cause or purpose).

Some well-known examples of verbal nouns are فتح fatḥ (see Fatah) (Form I), تنظيم tanẓīm (Form II), جهاد jihād (Form III), إسلام islām (Form IV), انتفاضة intifāḍah (feminine of Form VIII verbal noun), and استقلال istiqlāl (Form X).

Regular verb conjugation for person-number, tense-aspect-mood, and participles

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'. Most of the final short vowels are often omitted in speech, except the vowel of the feminine plural ending -na, and normally the vowel of the past tense second person feminine singular ending -ti.

The initial vowel in the imperative (which is elidable) varies from verb to verb, as follows:

• The initial vowel is u if the stem begins with two consonants and the next vowel is u or ū.
• The initial vowel is i if the stem begins with two consonants and the next vowel is anything else.
• There is no initial vowel if the stem begins with one consonant.

In unvocalised Arabic, katabtu, katabta, katabti and katabat are all written the same: كتبت. 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.

ا (alif) in final ـُوا (-ū) is silent.

Weak roots

Roots containing one or two of the radicals و w (wāw), ي y (yāʾ ) or ء ʾ (hamzah) often lead to verbs with special phonological rules because these radicals can be influenced by their surroundings. Such verbs are called "weak" (verba infirma, 'weak verbs') and their paradigms must be given special attention. In the case of hamzah, these peculiarities are mainly orthographical, since hamzah is not subject to elision (the orthography of ء hamzah and ا alif is unsystematic due to confusion in early Islamic times).^{[citation needed]} According to the position of the weak radical in the root, the root can be classified into four classes: first weak, second weak, third weak (or final weak) and doubled, where both the second and third radicals are identical. Some roots fall into more than one category at once.

Doubled roots

The following shows a paradigm of a typical Form I doubled verb مَدَّ (يَمُدُّ) (root: م-د-د) madda (yamuddu) 'to extend', parallel to verbs of the فَعَلَ (يَفْعُلُ) faʿala (yafʿulu) type. See notes following the table for explanation.

All doubled verbs are conjugated in a parallel fashion. 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. The regular stems are identical to the stem forms of sound verbs, while the modified stems have the two identical consonants pulled together into a geminate consonant and the vowel between moved before the geminate. In the above verb مَدَّ (يَمُدُّ) madda (yamuddu) 'to extend (s.th.)', the past stems are مَدَدـ madad- (regular), مَدّـ madd- (modified), and the non-past stems are مْدُدـ mdud- (regular), مُدّـ mudd- (modified). In the table, places where the regular past stem occurs are in silver, and places where the regular non-past stem occurs are in gold; everywhere else, the modified stem occurs.

No initial vowel is needed in most of the imperative forms because the modified non-past stem does not begin with two consonants.

The concept of having two stems for each tense, one for endings beginning with vowels and one for other endings, occurs throughout the different kinds of weaknesses.

Following the above rules, endingless jussives would have a form like تَمْدُد tamdud, while the corresponding indicatives and subjunctives would have forms like تَمُدُّ tamuddu, تَمُدَّ tamudda. 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. These are the only irregular endings in these paradigms, and have been indicated in boldface. The masculine singular imperative likewise has multiple forms, based on the multiple forms of the jussive.

There are various types of doubled Form I verbs:

Sound verbs

Sound verbs are those verbs with no associated irregularities in their constructions. Verbs with irregularities are known as weak verbs; generally, this occurs either with (1) verbs based on roots where one or more of the consonants (or radicals) is w (wāw, و), y (yāʾ, ي) or the glottal stop ʾ (hamzah, ﺀ); or (2) verbs where the second and third root consonants are the same.

Some verbs that would be classified as "weak" according to the consonants of the verb root are nevertheless conjugated as a strong verb. This happens, for example:

• Largely, to all verbs whose only weakness is a hamzah radical; the irregularity is in the Arabic spelling but not the pronunciation, except in a few minor cases.
• Largely, to all verbs whose only weakness is a y in the first radical (the "assimilated" type).
• To all verbs conjugated in Forms II, III, V, VI whose only weakness is a و w or ي y in the first or second radicals (or both).

Form VIII assimilations

Form VIII has a ـتـ -t- that is infixed into the root, directly after the first root consonant. This ـتـ -t- assimilates to certain coronal consonants occurring as the first root consonant. In particular, with roots whose first consonant is د، ز، ث، ذ، ص، ط، ض، ظ d z th dh ṣ ṭ ḍ ẓ, the combination of root and infix ت t appears as دّ، زد، ثّ، ذّ، صط، طّ، ضط، ظّ dd zd thth dhdh ṣṭ ṭṭ ḍṭ ẓẓ. That is, the t assimilates the emphasis of the emphatic consonants ص، ط، ض، ظ ṣ ṭ ḍ ẓ and the voicing of د، ز d z, and assimilates entirely to the interdental consonants ث، ذ، ظ th dh ẓ. 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. (ض ḍ was possibly an emphatic voiced alveolar lateral fricative /ɮˤ/ or a similar affricated sound /dɮˤ/ or /dˡˤ/; see the article on the letter ض ḍād.)

Defective (third-weak) verbs

Other than for Form I active, there is only one possible form for each verb, regardless of whether the third root consonant is و w or ي y. All of the derived third-weak verbs have the same active-voice endings as (فعى (يفعي faʿā (yafʿī) verbs except for Forms V and VI, which have past-tense endings like (فعى (يفعي faʿā (yafʿī) verbs but non-past endings like (فعي (يفعى faʿiya (yafʿā) verbs. The passive-voice endings of all third-weak verbs (whether Form I or derived) are the same as for the (فعي (يفعى faʿiya (yafʿā) verbs. The verbal nouns have various irregularities: feminine in Form II, -in declension in Form V and VI, glottal stop in place of root w/y in Forms VII–X.

The active and passive participles of derived defective verbs consistently are of the -in and -an declensions, respectively.

Defective Form IX verbs are extremely rare. Heywood and Nahmad list one such verb, iʿmāya 'be/become blind', which does not follow the expected form اعميّ *iʿmayya.^[2] They also list a similarly rare Form XI verb اعمايّ iʿmāyya 'be/become blind' — this time with the expected form.

Hollow (second-weak) verbs

Only the forms with irregularities are shown. The missing forms are entirely regular, with w or y appearing as the second radical, depending on the root. There are unexpected feminine forms of the verbal nouns of Form IV, X.

Assimilated (first-weak) verbs

When the first radical is w, it drops out in the Form I non-past. Most of the derived forms are regular, except that the sequences uw iw are assimilated to ū ī, and the sequence wt in Form VIII is assimilated to tt throughout the paradigm. The following table only shows forms with irregularities in them.

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'). Root: و-ع-ل

When the first radical is y, the forms are largely regular. The following table only shows forms that have some irregularities in them, indicated in boldface. Root: ي-ع-ل

Doubled verbs

Root: ف-ل-ل

Hamzated verbs

The largest problem with so-called "hamzated" verbs (those with a glottal stop ʾ or "hamzah" as any of the root consonants) is the complicated way of writing such verbs in the Arabic script (see the article on hamzah for the rules regarding this). In pronunciation, these verbs are in fact almost entirely regular.

The only irregularity occurs in verbs with a hamzah ء as the first radical. A phonological rule in Classical Arabic disallows the occurrence of two hamzahs in a row separated by a short vowel, assimilating the second to the preceding vowel (hence ʾaʾ ʾiʾ ʾuʾ become ʾā ʾī ʾū). This affects the following forms:

• The first-person singular of the non-past of Forms I, IV and VIII.
• The entire past and imperative of Form IV.

In addition, any place where a hamzat al-waṣl (elidable hamzah) occurs will optionally undergo this transformation. This affects the following forms:

• The entire imperative of Form I.
• The entire past and imperative of Form VIII, as well as the verbal noun of Form VIII.

There are the following irregularities:

• The common verbs ʾakala (أكل; root: ء-ك-ل) 'eat', ʾakhadha (أخذ; root: ء-خ-ذ) 'take', ʾamara (أمر; root: ء-م-ر) 'command' have irregular, short imperatives kul, khudh, mur.
• Form VIII of the common verb ʾakhadha 'take' is ittakhadha 'take on, assume', with irregular assimilation of the hamzah.
• The common verb saʾala yasʾalu 'ask' has an alternative non-past yasalu with missing hamzah.

Doubly weak verbs

Doubly weak verbs have two "weak" radicals; a few verbs are also triply weak. Generally, the above rules for weak verbs apply in combination, as long as they do not conflict. The following are cases where two types of weaknesses apply in combination:

• Verbs with a w in the first radical and a w or y in the third radical. These decline as defective (third-weak) verbs, and also undergo the loss of w in the non-past of Form I, e.g. waqā yaqī 'guard', wafā yafī 'complete, fulfill (a promise)', waliya yalī 'be near, follow'. These verbs have extremely short imperatives qi fi li (feminine qī fī lī, masculine plural qū fū lū, feminine plural iqna ifna ilna), although these are not normally used in Modern Standard Arabic. Similarly, verbs of this sort in Form IV and Form VIII are declined as defective but also have the normal assimilations of w-initial verbs, e.g. Form IV awfā yūfī 'fulfill a vow', Form VIII ittaqā yattaqī 'fear (God)', augmentations of wafā yafī and waqā yaqī, respectively (see above).
• Verbs with a hamzah in the first radical and a w or y in the third radical. These decline as defective (third-weak) verbs, and also undergo the assimilations associated with the initial hamzah, e.g. the common verb ʾatā yaʾtī 'come' (first singular non-past ʾātī 'I come') and the related Form IV verb ʾātā yuʾtī 'bring' (first singular non-past ʾūtī 'I bring').

The following are examples where weaknesses would conflict, and hence one of the "weak" radicals is treated as strong:

• Verbs with a w or y in both the second and third radicals. These are fairly common, e.g. rawā yarwī 'recount, transmit'. These decline as regular defective (third-weak) verbs; the second radical is treated as non-weak.
• Verbs with a w in the first radical and the second and third radicals the same. These verbs do not undergo any assimilations associated with the first radical, e.g. wadda (wadidtu) yawaddu 'to love'.
• Verbs with a hamza in the first radical and the second and third radicals the same. These verbs do not undergo any assimilations associated with the first radical, e.g. ʾajja yaʾujju 'burn', first singular non-past ʾaʾujju 'I burn', despite the two hamzahs in a row.

The following are cases with special irregularities:

• Verbs with a w or y in the second radical and a hamzah in the third radical. These are fairly common, e.g. the extremely common verb jāʾa yajīʾu 'come'. The only irregularity is the Form I active participle, e.g. jāʾin 'coming', which is irregularly declined as a defective (third-weak) participle (presumably to avoid a sequence of two hamzahs in a row, as the expected form would be *jāʾiʾ).
• The extremely common verb raʾā yarā 'see'. The hamzah drops out entirely in the non-past. Similarly in the passive, ruʾiya yurā 'be seen'. The active participle is regular rāʾin and the passive participle is regular marʾīy-. The related Form IV verb arā yūrī 'show' is missing the hamzah throughout. Other augmentations are regular: Form III rāʾā yurāʾī 'dissemble', Form VI tarāʾā yatarāʾā 'look at one another', Form VIII irtaʾā yartaʾī 'think'.
• The common verb ḥayiya yaḥyā 'live', with an alternative past tense ḥayya. Form IV aḥyā yuḥyī 'resuscitate, revive' is regular. Form X istaḥyā yastaḥyī 'spare alive, feel ashamed' also appears as istaḥayya and istaḥā.