Tones change the meaning entirely
Vietnamese uses six tones, and the same string of letters said with a different pitch pattern can mean a completely different word. Native speakers are generally still able to follow a foreigner's intended meaning from context even with flat, non-tonal pronunciation, so it is worth attempting these phrases rather than skipping them out of fear of getting the tone wrong.
North and south use different everyday words
Vietnamese has noticeable regional differences between the northern (Hanoi-based) and southern (Ho Chi Minh City-based) dialects, including some everyday vocabulary and pronunciation. The phrases above are understood nationwide, even where a few local variants also exist.
Frequently Asked Questions
Do I need to worry about getting the tones exactly right?
Not for basic travel purposes. Context, gestures, and a friendly tone usually carry the meaning even with imperfect tones, and most Vietnamese speakers are used to hearing an imperfect accent from learners.
Is Vietnamese written with Chinese characters?
No, not anymore. Vietnamese is written with a Latin-based alphabet called Quốc Ngữ, developed a few centuries ago, though it uses extra accent marks to represent tones and sounds that don't exist in English.