Match each base form to its past simple form.

Explication

The past-simple pattern mix here is 4 verbs using separate changes for past and participle, 1 verb using a participle that returns to the base pattern, and 1 verb using one shared past-and-participle pattern. The past-simple match follows the verb's own irregular class, so visual resemblance to another verb's form is not enough; the dominant class is separate changes for past and participle (4 of 6), with 3 pattern classes represented.