1. A computer-implemented method of automatic speech recognition, comprising: propagating, by at least one processor, tokens that are each associated with one or more sounds from a recording of a person talking and that is at least part of a word, through a weighted finite state transducer (WFST) having arcs and words or word identifiers as output labels of the WFST, and comprising placing word sequences into a word lattice; generating, by at least one processor, a word history designation for individual tokens when a word is established at a token propagating along one of the arcs with an output symbol, wherein the word history designation indicates a word sequence; and determining, by at least one processor, whether or not two or more tokens should be combined to form a single token in a state of the WFST by using, at least in part, the word history designations so that the recorded sounds are transformed into data that indicates recognition of an utterance by using, at least in part, the word history designations.