Tone marks are important in Vietnamese as it is a tonal language. It is important that you get them right, both in pronunciation and writing. There are only 5 tone marks and one empty/no mark tone; together, they make 6 tones in total. I would recommend looking up some videos to help with your listening and pronunciation. Also, not too long ago, I’ve made a post about how high/low your voice should be according to the Southern accent.
1. Không dấu/Unmarked (mid-level tone): Slightly higher than normal pitch. It’s typically described as the lvel tone
2. Dấu Sắc/Acute (high-rising tone): The pitch starts at around the mid-level tone and then rises sharply
3. Dấu Huyền/Grave (low-falling tone): The pitch starts lower than mid-level tone and then drops off, but not sharply
4. Dấu Hỏi/Hook Above (low-rising tone): The pitch starts lower than mid-level tone then rises. Sounds like the questioning tone in English.
5. Dấu Ngã/Tilde (high-rising broken tone): The pitch starts a little above the mid-level tone, dips, then rises sharply
6. Dấu Nặng/Dot Below (low-falling broken tone): The pitch starts slightly lower than the low-falling tone, then drop very sharply
- NOTE: In spoken Vietnamese, there is very little, if any, distinction between the hook above accent mark (dấu hỏi) and the tilde accent mark (dấu ngã)