Some syllables (written Chinese characters) have special pronunciations in Peking opera. This is due to the collaboration with regional forms and kunqu that occurred during the development of Peking opera. For example, 你, meaning "you", may be pronounced "li", as it is in the Anhui dialect, rather than the Standard Chinese "ni". 我, meaning "I" and pronounced "wo" in Standard Chinese, becomes "ngo", as it is pronounced in the dialect of Suzhou. In addition to pronunciation differences that are due to the influence of regional forms, the readings of some characters have been changed to promote ease of performance or vocal variety. For example, "zhi", "chi", "shi", and "ri" sounds do not carry well and are difficult to sustain, because they are produced far back in the mouth. Therefore, they are performed with an additional "i" sound, as in "zhii".