Is it permissible and valid to recite the Quran for someone who does not know how to pronounce one or more letters, and can this be done with تدبر (contemplation), and how can the reciter contemplate meanings they do not know, and should the recitation be silent or audible?

It is not permissible for a Muslim to recite the Qur’an if they do not know how to pronounce the letters before learning them, because recitation that alters the structure of words or corrupts their meaning is not permissible. A person must recite the Qur’an with a sound and correct recitation, even if it requires time to spell out the words and articulate them properly, because the Qur’an is the word of Allah, and distorting it is forbidden. Whoever does not know how to pronounce the letters should refrain from reciting until they learn. There is no harm in looking at the Mushaf and pondering its meanings without reciting. Pondering involves reflecting on the meaning and contemplating it. What aids in pondering is sincerity to Allah, supplication, emptying the heart of distractions, and avoiding sins.