Prayer: Is prayer valid with recitation mistakes?

Practical Laws of Islam as per the teachings of Imam Khamenei

Prayer: Is prayer valid with recitation mistakes?

English:

Question #474:

If someone makes some mistake — due to his negligence or accent — in the recitation of the Fātiḥah and the other chapter, or in the pronunciation of the vowels, for example, ‘yūlid’ instead of ‘yūlad,’ what will be the rule of such a prayer?

Answer #474:

If he makes this mistake intentionally, his prayer is void. Also, if he is a blameworthy ignorant person (who can learn it), his prayer is, by obligatory caution, void. However, if he was a non-blameworthy ignorant person and offered the previous prayer like that thinking that it was the correct way, his prayers are ruled as correct and he is not required to repeat, or make up for, it in qaḍā’.

-Imam Khamenei, Practical Laws of Islam, Importance and Conditions of Prayer