The rule is the default rule. Because 'sigma' is not available to the internet, the '$' will be used to represent a syllable: # --> #$ or $#. '#' = a word boundary. All word boundaries are syllable ...

A syllable is a beat of sound in a word. The beat can sometimes be part of a word, or the whole word. For example 'window' has two beats ('win' – 'dow') but 'door' had just one ('door').

There are a number of ways to make "the MASU-form of verbs" into "the dictionary form." First, if a verb has the vowel E in its syllable just before MASU, you remove MASU, and add RU to the verb.

A syllable is a beat of sound in a word. The beat can sometimes be part of a word, or the whole word. For example 'window' has two beats ('win' – 'dow') but 'door' had just one ('door').