Pronunciations can vary significantly within Vietnam (especially northern vs southern).

1. Hello - Xin chao - seen chow

2. thank you - Cam on - Gahm un

3. Sorry - Xin loi - seen loy

4. Yes - Vang - vung

5. No - Khong - Khom

6. I - Toi - doy

7. You - Anh / Chi - Ang (male) / chi (female)

8. Good - tot - tote

9. Bad - Khong tot - khom tote

10. How much - Bao nhieu - Bow nyew

11. Too expensive - Mac qua - Mahk qwa

12. Hotel - Khach San - Khack san

13. Ticket - Ve - Vee ah (pronounced similarly to "yeah" in English)

14: Hot - Nong - Nom

15: Cold - Lanh - Lang

16: Coffee - Ca phe - cah feh

17: Hot black coffee - Ca phe nong - Cah feh nom

18: Hot Coffee with milk - Ca phe sua nong - Cah feh swa nom

19: Iced Coffee with milk - Ca phe sua dac - Cah feh swa dahk

20: Tea - Tra - Chah

21: Oh my god - Oi gioi oi - oi zoi oi

22: You're welcome - Khong co' chi (khom go jee)

23: You're beautiful - Co dep qua (coh dep wah)

24: Smile - cuoi len (kuy leen)

25. bathroom - pho`ng ve^ sinh  (fonh veah sin) 

 See also:

Vietnamese language overview and list some most frequently used one-for-one correspondings