The source describes a sākin consonant as having its sound closed at its point of articulation before the next consonant emerges. A needless movement before the next sound can make the sākin seem vowelled.
Practice «قَدْ أَفْلَحَ»: the sākin dāl should be followed by a distinct hamzah, not by an extra vowel attached to dāl. The hamzah rule itself was treated in the previous level.
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How a sākin consonant is held
Correct Vowel Articulation — Fatḥah, Kasrah, Ḍammah, Ishbāʿ and Sukūn
The source describes a sākin consonant as having its sound closed at its point of articulation before the next consonant emerges. A needless movement before the next sound can make the sākin seem vowelled.
Practice «قَدْ أَفْلَحَ»: the sākin dāl should be followed by a distinct hamzah, not by an extra vowel attached to dāl. The hamzah rule itself was treated in the previous level.