Absence of a short vowel, always written above the letter itself
Shadda
Word stress, above the target letter, it becomes two letters to its origin
When the shadda is on some letters, it doesn't affect the sound of the letter or the vowel that comes with it. The only difference is in the pronunciation, we will have to strengthen a bit of the letter while pronouncing.
Fathatayn
Double fatha
Dammatayn
Double damma
Kasratayn
Double kasra
Fathatayn and Dammatayn are written above the letters, Kasratayn are written under the letters
Tanween Alfat'h
The equivalent is an, will give an extra sound N to the original sound of the normal fatha
Tanween Addam
The equivalent is un, will give an extra sound N to the original sound of the normal damma
Tanween Akasr
The equivalent is in, will give an extra sound N to the original sound of the normal kasra
