Ivie Hunt was barely 6 last spring and had just finished kindergarten when she shocked the hostess at a Denver Asian restaurant by chatting comfortably in Mandarin Chinese. “Here was this little blond, white girl having a full conversation with the hostess in Mandarin,” said her mother, Ann Hunt, who admitted to being a bit stunned herself. That kind of surprise may wear off as Mandarin Chinese becomes the first choice of a growing number of second-language learners. More language students are saying adios to the recent stampede to learn Spanish and huan ying — or welcome — to mastering a Chinese dialect now spoken by an estimated 100 million non-Chinese.