The pinyin method () refers to a family of input methods based on the pinyin method of romanization.
In the most basic form, the pinyin method allows a user to input Chinese characters by entering the pinyin of a Chinese character and then presenting the user with a list of possible characters with that pronunciation. However, there are a number of slightly different such systems in use, and modern pinyin methods provide a number of convenient features.
Advantages and disadvantages
The obvious advantage of pinyin-based input methods the ease of learning for Standard Chinese speakers. Those who are familiar with pinyin and are able to recognize the resulting characters would be able to input them with almost no training, compared to other input methods. It does not require the user to be able to construct the character from scratch, as one would do in written Chinese. Since all children in Mainland China are required to learn pinyin in school, pinyin is among the most popular input methods there.
For people who cannot speak Standard Chinese, the main advantage of pinyin becomes a disadvantage, as they will need to learn the Standard Chinese pronunciation of characters before they are able to use this input method. Also, because pinyin and other pronunciation-based input methods do not rely on the written formation of the character for input (as do stroke-based input methods like Cangjie), they may cause language attrition and skill loss in adults, and it may be a learning barrier for written Chinese in children.
Elements and features
Pinyin input methods differ in a number of possible aspects. Most pinyin input methods provide convenience features to speed up input. Some of these features can speed up typing immensely.
Conversion length
Conversion length input method is the buffer that holds the user input until it is converted into characters that would otherwise be unavailable from the keyboard.
In the most basic systems, one character is converted at a time. This makes a very time-consuming input process. Not only does the user have to select characters one at a time, it also means that the input system does not have the ability to prioritize character choices using word phrases, grammatical structure, or context. In addition, since the input method only supports one character at a time, it likely requires the user to type out the full pinyin spelling to narrow down the selection. This system still exists in embedded applications such as cell phones.
Common pinyin implementations on the computer today can hold up to a clause in pinyin before requiring a conversion. The method attempts to guess the appropriate characters by using word phrases from a dictionary, grammatical structure, and context.
Treatment of tones
Chinese is a tonal language. Tones can be used to further distinguish characters of the same sound. Many of the early single-character pinyin method implementations required input of tones in order to narrow down the character selection.
For the sake of convenience, tone selection is disabled by default in most modern pinyin systems on the computer. The user may have the option to enable it depending on the pinyin implementation.
Treatment of extended Latin characters (ü and ê) With the exception of intonation, there are two extended Latin vowels in pinyin. They are ü (U-umlaut) and ê (E-circumflex). Given that the US keyboard layout is the most common keyboard layout in China, any pinyin method implementation would need to be able to facilitate the input of those vowels on US keyboard.
Since the letter "v" is unused in Mandarin pinyin, it is universally used as an alias for ü. For example, typing "nv" into the input method would bring up the candidate list for .
The handling of ê is not as universal, since the character 欸 is the only commonly used character with this pronunciation. It is an interjection roughly equivalent to "Eh" in English. Some IMEs, such as Google Pinyin, merge it into "e", while others create an additional letter combination for it, such as "ea" or "eh", or "ei" in iOS. Others would simply drop this sound.
Treatment of hm, hng, ng, n
The character 嗯 (ng) can (or should) be written using the IBUS GNU/Linux and the Microsoft input method by typing "en".
Usage statistics and user dictionaries
Most modern input method implementations would adjust the positions of word candidates in the candidate list based on prior usage statistics. In addition, the input method would also support user-defined phrases via a user dictionary.