1. A system for building a custom word list for use in text operations on an electronic device comprising: a processor; and a memory storing instructions that, when executed by the processor, cause the processor to perform operations comprising: determining a source associated with a text item, identifying words in the text item composed by and associated with a user, and assigning a weighting to each identified word based in part on the source of the text item, wherein the source is determined based on an identity of the user associated with at least one portion of the text item.