What is the ruling on one who neglects the rules of tajwid, such as one who does not perform the connected elongation (madd al-muttasil)? Is it permissible to pray behind him?

Question:
The Honorable Shaykh, may Allah grant you success, says: What is the ruling on one who neglects the rules of recitation and tajwid, such as one who does not perform the elongations, especially the connected elongation? Is it permissible to pray behind him? My brother,

Answer:
What is required is to perfect the grammar so that one does not make a grammatical error that contradicts the rules of grammar. As for deviating from the rules of tajwid, these are supplementary; if one deviates from them, it does not cause harm. What is required is to regulate it grammatically in the language of the Qur'an in which it was revealed, by raising the nominative, lowering the genitive, making the accusative accusative, and making the jussive jussive. This is what is required; this is the tajwid that is required. As for the tajwid that involves idgham, ghunnah, and elongations, these are supplementary. If they are done without exaggeration, there is no harm. Even exaggeration is not permissible in them, but moderation in them is fine. These are complements; they are improvements.