"أ" is the first letter of the Arabic alphabet. It is pronounced as "alif" and has a unique shape that resembles a vertical line with a small diagonal stroke. In Arabic script, it can appear in different forms depending on its position in a word: initial, medial, or final. In terms of phonetics, "أ" represents a glottal stop sound, similar to the sound in the English word "uh-oh." It is also used as a vowel in various contexts. The letter "أ" can be found in many Arabic words, including أب (father) and أم (mother).