When I started my Vietnamese intensive course, a lot of non-linguistists I talked to said that the Chinese students would have an advantage because they already speak a tonal language. It is true that some Westerners could be completely stumped by tones, and just not get the language at all. But, a person who already speaks a tonal language does not have an advantage over a Westerner or a Korean or Japanese who is intelligent, motivated and who is trying to learn tones. Remember that a Cantonese or Mandarin speaker has mastered the tones of his or her language, not the tones of Vietnamese. Saying that someone from a tonal language would have an advantage is like saying people from languages with words, or sounds, or verbs or adjectives would have an advantage.