Let's first take a look at how to conjugate the Measure I verb. Measure I is the most inconsistent measure and the conjugations vary greatly. For this reason, I recommend that whenever you learn a Measure I verb that you learn the Perfect (Past) and Imperfect (Present) conjugations together.

The most notable variation for Measure I verbs is the short vowel that occurs on the middle consonant for both Perfect and Imperfect conjugations. In other words, if we look at that Arabic root كتب which means to write; the middle consonant is a ت. The short vowel that goes over this consonant will vary from verb to verb, sometimes it will be a fatha, sometimes a dhamma, and sometimes a kasra.


So how do we know which vowel to use? We consult the dictionary. I always use The Hans Wehr Dictionary of Modern Written Arabic.
When you look up the root كتب in the Hans Wehr dictionary, the entry will look like this:



The first term kataba tells us the voweling for the Perfect (Past) tense. The a corresponds to a fatha. In this case, kataba = كَتَبَ

The single italicized u tells us the vowel for the middle consonant in the Imperfect (Present) tense.
In this case, the u indicates a dhamma, thus he writes = يَكْتُبُ

The words in parentheses indicate the verbal nouns for measure I. Verbal nouns for Measure I vary greatly and there really is no way to predict them. So, when you learn a Measure I Perfect/Imperfect conjugation, you might as well learn the verbal noun along with it. You will find the full meaning of the verbal noun in a sub-entry underneath the main entry in the Hans Wehr dictionary.

It is extremely important to pay attention to what the middle vowel is. You must use it to form the imperative; plus you will just sound like an uneducated rube if you don't pronounce your verbs with the correct voweling when speaking Arabic.

The voweling pattern is the combination of the perfect voweling and the imperfect voweling. There are four main voweling patterns for Measure I, and verbs can be placed in categories according to these patterns. If we look at كَتَبَ \ يَكْتُبُ we see that this verb has a fatha in the perfect and a dhamma in the imperfect. This is the perfect fatha - imperfect dhamma pattern.

Now that we have been introduced to one of these patterns, let's look at the other three:

Perfect Kasra - Imperfect Fatha

Perfect - شَرِبَ He drank
Imperfect - يَشْرَبُ He drinks

Perfect Fatha - Imperfect Fatha

Perfect - ذَهَبَ - He went

Imperfect - يَذْهَبُ - He goes

There is a fifth voweling pattern that should be recognized. It often exists in the same root with other voweling patterns and it is usually listed further down in the entry. Look at this dictionary entry:

You will notice the green underlined portion has the voweling كَبَرَ \ يَكْبُرُ which means to exceed in age. The red underlined portion shows the fifth type of voweling, with a dhamma in both perfect and imperfect,

كَبُرَ \ يَكْبُرُ which means to be or become great, big. The voweling pattern (Perfect Dhamma - Imperfect Dhamma), always carries the meaning of to be or become (something).

You will probably not encounter this type of verb very often.

However, there is something worth remembering. Every verb of this type will have a corresponding adjective in the form of فَعِيلٌ. You will encounter this form of adjective very frequently.

The following table shows a list of these adjectives and their associated verbs:

The imperative الأمر is used when you issue a command or order to someone. For example:
Sit down.
Stand up.
Read your book.


The imperative is rather easy to form. Follow these simple steps:

• Start with the third person singular imperfect tense. Ex. he writes يَكْتُبُ
• Change the final vowel to a sukuun. يَكْتُبُ becomes يَكْتُبْ
• Remove the prefix. يَكْتُبْ becomes كْتُبْ
• If the first consonant has a sukuun, then it requires a helping vowel.
  • The helping vowel comes at the beginning of the verb and sits on an alif. The short vowel that sits on the middle root letter is used to determine what the helping vowel is.
  • If the middle vowel is a dhamma, then the helping vowel is a dhamma.
  • If the middle vowel is a fatha or a kasra, then the helping vowel is a kasra.
  • The Measure I imperative will never have a fatha as a helping vowel.
  • In our example, كْتُبْ has a sukuun so it requires a helping vowel. In this case the vowel over the second root letter is a dhamma. So, the helping vowel will be a dhamma that sits on an alif. Therefore, كْتُبْ becomes اُكْتُبْ.
  • The imperative of يَكْتُبُ is اُكْتُبْ
• If the verb is hollow or defective then the long vowel is dropped from the verb.

Perfect

Imperfect