This is a part of the Introduction to Wubi Input Method series.
I’ll begin explaining the logic structure behind Wubi. Lets start from the basics so you can build a framework for memorising all you need to type quickly and effectively.
Character codes
Wubi keyboard consists of 26 keys which conveniently correspond to Latin letters. The Z key is a wildcard key, and its actual function is often implementation dependent. Other 25 keys correspond to Wubi shapes. These are divided into 5 groups 5 keys each, which correspond to 5 basic calligraphy strokes, giving the method its name as I mentioned before. The shapes represent either whole characters (root characters or shortcuts to the most frequent characters), radicals (which the characters are composed of) or special isolation strokes (which distinguish characters with the same shapes). The shapes are generally input in the order in which corresponding radicals are written with special rules applied for root characters, shortcuts and isolation, and the total number of keys is limited four (first three and then the last). Therefore, each character can be assigned a code that is conveniently written with four or less Latin letters. When you can write with the character and know the Wubi rules (that are explained in this series), you can easily derive the code yourself, or you can look it up, for example 漢典 electronic dictionary lists Wubi codes even for the obscure characters.
Root shapes
First thing you need to memorise are root shapes. They are divided into groups according to basic calligraphy strokes. All the keys in one group are conveniently placed next to each other to that each group is a separate region of keys.
Region 1 ㇒ diagonal
The first region (green in the diagram below) is located in the left hand area of the top row (That is, QWERT. Have I mentioned that Wubi works perfectly with touch typing?) and includes shapes 金、人、月、白、禾, each of which starts with a diagonal stroke (short one in case of 白).
Region 2 ㇔ point
The second region (red in the diagram below) occupies the right hand area of the top row (YUIOP) and includes shapes 言、立、水、火、之, each of which starts with the point (in case of 水 think of its radical form 氵).
Region 3 ㇐ horizontal
The third region (magenta in the diagram below) corresponds to the left part of the middle row (ASDFG) and includes shapes 工、木、大、土、王, each of which, again, starts with the horizontal stroke.
Region 4 ㇑vertical
The fourth region (blue in the diagram below) contains the right part of the middle row (HJKL) plus M key in the bottom row and includes shapes 目、日、口、田、山, each of which – you guessed it right, starts with the vertical stroke. Also, note that all keys in the middle row in this region are closed shapes.
Region 5 ㇜㇇㇛㇌㇖ break
The last region (orange in the diagram below) consists of the bottom row keys except X and M (That is, XCVBN) and includes shapes 纟又女子已 that start with different broken strokes.
The meaning of root shapes and regions
The first obvious use for root shapes is to input the character itself. The code for the root shape character is the key repeated four times. Thus, if you want to input 金, you type qqqq, if you want to input 木, you type ssss, if you want to input 土, you type ffff, and so on.
You don’t necessary have to type full four letter codes. As long as there is no ambiguity, you can type first letters of a code followed by a space. Most of the root shape characters can be input with three letter codes, 立、水、之 and 子 can be input with two letter codes, while 工 and 人 can be input with the single a or w (This is because the shortcut characters, which will be explained further in the series, in case of these keys are the same as root characters due to their high frequency of use).
The code xxx (or xxxx) is the only Wubi code that corresponds to a radical that cannot be used as an independent character (纟).
The regions and the basic strokes serve not only as mnemonics for root shapes, but also play a very important role in isolation rules, which we will likewise explore later in the series.
Next chapter: Character Composition and Secondary Shapes.