Verbs
reference — free to readBuild a form
Pick a verb and a form. The answer is shown in the pieces the rule assembles it from — which is the part a table cannot show you.
The row shift, in full
This one table is the whole godan class. The last two columns are the て-form, which does not shift but collapses.
う takes わ in the あ column, not あ: 買う becomes 買わない.