Verbs in which the middle root letter is waw or ya و ي
Are traditionally known as “hollow verbs” and are subject to certain phonetic changes.
In the past tense, this “weak letter” is usually replaced by an Alif, so that we could describe this using the pattern:
for example you will often come across these common verbs which fit the pattern:
In the present tense the middle letter is the original root middle letter (this can be found out by checking a dictionary, or simply learned.)
So that from the above verbs we get:
These verbs are then conjugated as normal.
nb: It is important to note that because these middle root letters are seen as “weak” sometimes they can be pushed out and there will be no long vowel in the word at all! This happens whenever the long vowel would have been followed by a letter with a sukoon. Eg:
In the past tense first person of كان
we get the conjugation :
This is because of the rule that you never should have a long vowel followed by a letter with a sukoon
The long vowel has been retained in the small way of placing a damma on the kaf. So we can say that in a way the long vowel is squeezed into its equivilent small vowel.