Hot answers tagged pinyin
The correct one should be bu2 zai4 hu. Unless there is an emphasis for "NOT" CARE, a 4th tone bu4 is then used, but I rarely hear that as a native speaker. Let's review the tone change rule for 不， A second tone bu2 is used only when the tone of next character is a 4th tone. A forth tone bu4 is used if the tone of next character is 1st, 2nd or 3rd tone.
Only top voted, non community-wiki answers of a minimum length are eligible