Letters as mails that you receive: 信 (xin)
It's "开"。
迈克
唐娜 (Tángnà)
Chinese doesn't have letters, each word is a specific character. It would most likely be the exact same as English.
Chinese does not use letters... this question can not be answered. Chinese instead uses character-words and thus only old, traditional words can be used.
Unlike Western languages like French, German, and English, Chinese does not have an alphabet. Written Chinese doesn't have letters that spell out words. Instead, it has characters that represent the different words of the language. The character for "open" is 開. In Simplified Chinese this is written 开.
you don't SPELL words in Chinese Each has a different character instead of a group of letters. Haley in Chinese is 海利 (if your computer can show Chinese characters), pronounced as "hi-li". If you have to spell it, then it's spelled "hai li".
麻雀 ma(2) que(4)
It is not possible to answer this question because of the special Chinese characters. You are welcomed in Chinese, is spelled by spelling out the individual letters going forward.
You write it like "八婆" (ba1 po2)
安德里安娜 an de li an na
SpongeBob goes to China would be written in Chinese characters as 海绵宝宝去中国.