Fathah, kasrah and dammah can affect both Arabic grammar and meaning. Replacing the prescribed vowel of a letter is an obvious recitation error.
الْحَمْدُ لِلّٰهِ
All praise belongs to Allah.
The final consonant in الْحَمْدُ carries dammah in this expression. Reading it with another short vowel fails to preserve the prescribed vocalization.
The lesson is practical: correct consonants alone are not enough. Their vowels, doubling signs and sukun must also be observed. Together they determine accurate recitation.