Without Tajweed, the meaning of words in Arabic can change drastically. For example, the Arabic letter and Kaaf (ك) have different points of articulation. Mispronouncing one for the other can alter the word Qalb (heart) to Kalb (dog), completely changing the meaning of a verse. This highlights the critical need for accurate recitation.
You can download detailed Malayalam Tajweed books through the following sources: quran tajweed rules in malayalam pdf