10. A graphical user interface on a portable electronic device with memory and one or more processors to execute one or more programs stored in the memory, the graphical user interface comprising: an input sequence of one or more alphabet characters; one or more partial word suggestions that satisfy predefined usage frequency criteria with respect to the input sequence, each partial word suggestion comprising a concatenation of the input sequence and two or more additional alphabet characters and the partial word by itself is not a complete word; wherein: the input sequence of one or more alphabet characters are received from a user; a character sequence data tree structure is identified, each node of the character sequence tree corresponding to a distinct character sequence, the input sequence corresponding to a first node in the character sequence tree; and one or more partial word suggestions corresponding to one or more descendent nodes of the first node that have values above a predefined threshold are selected, wherein a respective value for a respective descendent node of the first node is the usage frequency weight of the respective descendent node divided by the usage frequency weight of the first node.
10. A graphical user interface on a portable electronic device with memory and one or more processors to execute one or more programs stored in the memory, the graphical user interface comprising: an input sequence of one or more alphabet characters; one or more partial word suggestions that satisfy predefined usage frequency criteria with respect to the input sequence, each partial word suggestion comprising a concatenation of the input sequence and two or more additional alphabet characters and the partial word by itself is not a complete word; wherein: the input sequence of one or more alphabet characters are received from a user; a character sequence data tree structure is identified, each node of the character sequence tree corresponding to a distinct character sequence, the input sequence corresponding to a first node in the character sequence tree; and one or more partial word suggestions corresponding to one or more descendent nodes of the first node that have values above a predefined threshold are selected, wherein a respective value for a respective descendent node of the first node is the usage frequency weight of the respective descendent node divided by the usage frequency weight of the first node. 12. The graphical user interface of claim 10 , further comprising a plurality of sequences, each of the plurality of sequences comprising a concatenation of the input sequence and a distinct alphabet character from a predefined set of alphabet characters.