►Form I Doubled Verbs
Perfective form I doubled verbs have an omitted short vowel.
| fa“al(a) | ||
| fa“il(a) | → | fa“l(a) |
| fa“ul(a) |
However, if we were to omit the vowel in the imperfective, we would get the following:
| yaf“al(u) | ||
| yaf“il(u) | → | yaf”l(u) |
| yaf“ul(u) |
Because the a between the first two root-letters is deleted in the imperfective, we would get yaf”l(u) which contains a three-consonant cluster that is unpronounceable.
Therefore, they had to keep the green short vowel in these verbs, but since the resultant structure contained -CCvC, like forms IV, X & QIV, they treated it in a similar manner and displaced the green vowel back -CCvC → -CvCC.
| yaf”al(u) | yafa“l(u) | |
| yaf”il(u) | → | yafi“l(u) |
| yaf”ul(u) | yafu“l(u) |
Example, the verb:
| Original Form | Doubled Verb |
| عَدَدَ | عَدَّ |
| “adad(a) | “add(a) |
| (He) counted | |
This is an u verb, it will become:
| Original Form | Doubled Verb |
| يَعْدُدُ | يَعُدُّ |
| ya“dud(u) | ya“udd(u) |
| (He) counts | |
| المُضَاْرِعُ الْمَرْفُوْعُ Indicative Imperfective (Active Voice) عَدَّ : فَعَلَ | |||
| S I N G U L A R | (I) count | ‘a“udd(u) | أَعُدُّ |
| (You masc.) count | ta“udd(u) | تَعُدُّ | |
| (You fem.) count | ta“uddeen(a) | تَعُدِّيْنَ | |
| (He) counts | ya“udd(u) | يَعُدُّ | |
| (She) counts | ta“udd(u) | تَعُدُّ | |
| D U A L | (You masc.) count | ta“uddaan(i) | تَعُدَّاْنِ |
| (They masc.) count | ya“uddaan(i) | يَعُدَّاْنِ | |
| (They fem.) count | ta“uddaan(i) | تَعُدَّاْنِ | |
| P L U R A L | (We dual/plu.) count | na“udd(u) | نَعُدُّ |
| (You masc.) count | ta“uddoon(a) | تَعُدُّوْنَ | |
| (You fem.) count | ta“dudn(a) | تعْدُدْنَ | |
| (They masc.) count | ya“uddoon(a) | يَعُدُّوْنَ | |
| (They fem.) count | ya“dudn(a) | يَعْدُدْنَ | |
The verb stem is restored to its original form in the feminine plural conjugations.
Thus, form I doubled verbs change from verbs with an omitted vowel in the perfective to verbs with a displaced-back vowel in the imperfective.
Note that imperfective form I doubled verbs are mostly u verb. There are few that are i or a verbs and most of these are classical verbs.
Some a and i verbs:
| Imperfective | Perfective | ||
| yazall(u) | يَظَلُّ | zall(a) | ظَلَّ |
| (he) remains/stays | (he) remained/stayed | ||
| yamall(u) | يَمَلًُّ | mall(a) | مَلَّ |
| (he) becomes bored | (he) became bored | ||
| yakall(u) | يَكَلَّ | kall(a) | كَلَّ |
| (he) becomes worn out | (he) became worn out | ||
| yafirr(u) | يَفِرَّ | farr(a) | فَرَّ |
| (he) escapes | (he) escaped | ||
| yakhiff(u) | يَخِفُّ | khaff(a) | خَفَّ |
| (he) becomes light | (he) was/became light | ||
| yaqill(u) | يَقِلُّ | qall(a) | قَلَّ |
| (he/it) becomes few/little | (he/it) was/became few/little | ||
| yahinn(u) | يَحِنَّ | hann(a) | حَنَّ |
| (he) yearns | (he) yearned | ||
| yarinn(u) | يَرِنَّ | rann(a) | رَنَّ |
| (he) rings | (he) rang | ||
| ya‘inn(u) | يَئِنَّ | ‘ann(a) | أَنَّ |
| (he) moans | (he) moaned | ||
More examples of i verbs:
| Yaf”il(u)→ yafi“l(u) | ||||
| شَبَّ | حَرَّ | جَلَّ | شَذَّ | خَرَّ |
| شَطَّ | شَحَّ | فَحَّ | حَبَّ | جَدَّ |
| نَسَّ | دَمَّ | دَرَّ | ||
| Conjugation of Doubled Verbs | |||
| Perfective | Imperfective | ||
| 1st person | untie | 1st person | don’t untie |
| 2nd person | untie | 2nd person | untie only with the feminine plural |
| 3rd person | untie only with the feminine plural | 3rd person | untie only with the feminine plural |
| Conjugation of Doubled Verbs | |||
| Perfective | Imperfective | ||
| Forms I, VII, VIII, IX & XI | omitted short vowel | Forms VII, VIII, IX & XI | omitted short vowel |
| Forms IV, X & QIV | displaced-back short vowel | Forms I, IV, X & QIV | displaced-back short vowel |
2) Mithaal Verbs