Rabi shrahli sadri wa ya sirli amri wah’lul ukda taminli sani yafkahu qouli.
O my lord! Open my heart, make my work easy for me, and remove the impediment from my speech so that they may understand my speech.
Recite the above verses as much as you can, especially before you sit for studies, recite at least 11 times. Inshallah you will get good marks, and get success in whatever career you choose, by Allah’s mercy and grace, Ameen
Islamic Duas and Supplications 