“Ta-llāhi taftaʾu tadhkuru Yūsuf”
“By God, you will not cease remembering Joseph.” (Yūsuf 12:85, excerpt)
The verb conveys “you will not cease”; the equivalent negative construction “lā taftaʾ” makes the intended sense clear. The oath and the established Arabic idiom support this reading.
“Alā inna ʿĀdan kafarū rabbahum”
“Truly, ʿĀd denied their Lord.” (Hūd 11:60, excerpt)
The verb’s relationship may be explained as disbelieving in their Lord or showing ingratitude toward their Lord’s favor.
These are not arbitrary insertions. Patterns of usage, surrounding discourse and the rhetorical situation jointly determine what grammatical relationship should be understood.