how can i imrove my grammer???

someone or somebody......PLEASE help me to improve my grammar.....next year i will sit for a MUET test.....but my grammar was my weakness.....i have to improve it quickly......actually this is my problem when learning English...i cant go through it....this problem since i was in standard 1....i never got A in my English....i always got B....B.....and B for my English subject.... i dont want this happen to my band in MUET exam....PLEASE somebody give a tips for me so that i can improve my grammar.....PLEASE!!!!!!!!..........