1. A computer-implemented method, comprising: identifying, using one or more computers, a first web page that includes a form associated with a particular action; identifying, using one or more computers, a second web page comprising a hyperlink that references the form of the first web page and that comprises hyperlink text; identifying, using one or more computers, the hyperlink text associated with the hyperlink in the second web page that references the form; adding the identified hyperlink text to a set of phrases that is used for generating an action initiation grammar associated with the particular action; generating the action initiation grammar associated with the particular action using the set of phrases; receiving an utterance; obtaining, using an automated speech recognizer, a transcription of the utterance; determining that at least a portion of the transcription of the utterance is included in the action initiation grammar associated with the particular action; and triggering the particular action to be performed in response to determining that at least a portion of the transcription of the utterance is included in the action initiation grammar associated with the particular action.
2. The method of claim 1 , wherein generating the action initiation grammar associated with the particular action further comprises: identifying a frequency of occurrence of a particular phrase of the set; and generating the action initiation grammar based on the identified frequency of occurrence of the particular phrase.