352a553d_gular_Verbs___UsingEnglish_com__Past_Participle
[Base Form] Soothsay [Past Simple] Soothsaid [3rd Person Singular] Soothsays [Present Participle / Gerund] Soothsaying [Past Participle] 
Soothsaid
English Irregular Verbs - UsingEnglish.com