1. A method to model and transfer prosody of tag questions across languages, the method comprising: receiving speech of a first person speaking in a first language; analyzing the speech in the first language using automatic speech recognition; extracting prosodic parameters of the speech in the first language and outputting text in the first language corresponding to the speech in the first language based on the analyzing; searching the speech in the first language for a tag question in the first language; translating the text in the first language to text in a second language; outputting translated speech in the second language that is translated from the speech in the first language based on the translated text in the second language; analyzing the speech in the first language to find speech segments that correspond to the tag question in the first language; extracting a fundamental frequency from the speech segments that correspond to the tag question in the first language; fitting a stylized smooth contour to the fundamental frequency; mapping the stylized smooth contour into a corresponding part of pitch range of the speech in the second language; extracting a fundamental frequency from the speech segments that correspond to the tag question in the first language; extracting a fundamental frequency from the speech segments that correspond to the tag question in the second language based on the extracted prosodic parameters of the speech in the first language; stretching or contracting the stylized smooth contour over time; aligning the stylized smooth contour with corresponding speech segments in the second language that correspond to the tag question; and applying the smooth contour to the speech in the second language.
2. The method of claim 1 , wherein the stylized smooth contour is a cubic spline.