It Is Obligatory To Recite Al-Fatihah In Every Rak'ah; If A Person Cannot Recite Al-Fatihah Or Cannot Learn It, Then He Should Recite Whatever Else He Can Manage Sahih Muslim 394 d

Arabic hadith text
وَحَدَّثَنَاهُ إِسْحَاقُ بْنُ إِبْرَاهِيمَ، وَعَبْدُ بْنُ حُمَيْدٍ، قَالاَ أَخْبَرَنَا عَبْدُ الرَّزَّاقِ، أَخْبَرَنَا مَعْمَرٌ، عَنِ الزُّهْرِيِّ، بِهَذَا الإِسْنَادِ مِثْلَهُ وَزَادَ فَصَاعِدًا
Translation
This hadith has also been transmitted by Ma'mar from al-Zuhri with the same chain of transmitters with the addition of these words

" and something more".