Answered by Shaykh Amjad Rasheed
If one is reciting the fatiha and says “ihdeena” adding a “ya” [s. for elongation], does this invalidate his prayer?
Her prayer is not invalidated by this, as the erudite scholar, Imam al-Sharqawi, said in his Hashiyat on the Sharh al-Tahrir, (1/186), “because it does not change the meaning.” However, it is obligatory for this person to learn the correct way of reciting it, for he is a sinner if he does not.
Amjad Rasheed
[Translated by Sr. Shazia Ahmad]