Verbs with additional contractions and shortenings
Many verbs derive from Germanic strong verbs, which make many of their inflected forms through vowel gradation, as can be observed in Modern English patterns.
Where SAYS and said are pronounced with a short vowel /ɛ/. The verb do has a similar vowel shortening in DOES and DONE.
To find the correct form, you can use an online database of the irregular verbs.
For example: irregular verb SAY