Pinyin is a Romanization method for representing the spoken sounds of Chinese characters. For example, the Chinese character 我 can be represented in Pinyin as wǒ or wo3, meaning that this character is pronounced in the third tone.
Either numbers or tone marks are acceptable in Pinyin, but tone marks are a bit easier to read. So how do you add tone marks to a Pinyin text?
There are several software tools that handle this task. For example, pinyin.info has an online converter that changes tone numbers to tone marks. Another one at mandarintools.com converts several types of Romanization, including Bopomofo.
These are just a few of the software tools available for writing Pinyin tone marks. If you have a favorite, please let us know by leaving a comment.