The book links fatḥah with infitāḥ al-fam, an appropriately open mouth. This does not call for an exaggerated jaw movement: the aim is a clear short /a/-like sound, not a kasrah- or ḍammah-like sound.
Practice: say «بَ، تَ، دَ» separately while retaining each consonant’s point of articulation. Check that the vowel stays open and short rather than sliding toward «بِ» or «بُ».
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Fatḥah: opening the mouth
Correct Vowel Articulation — Fatḥah, Kasrah, Ḍammah, Ishbāʿ and Sukūn
The book links fatḥah with infitāḥ al-fam, an appropriately open mouth. This does not call for an exaggerated jaw movement: the aim is a clear short /a/-like sound, not a kasrah- or ḍammah-like sound.
Practice: say «بَ، تَ، دَ» separately while retaining each consonant’s point of articulation. Check that the vowel stays open and short rather than sliding toward «بِ» or «بُ».