Present participle; Past participle - frightening - frightened Present - frighten - frighten - frightens - frighten - frighten - frighten Past - frightened - frightened - frightened - frightened - frightened - frightened Future - will frighten - will frighten - will frighten - will frighten - will frighten - will frighten Present conditional - would frighten - would frighten - would frighten - would frighten - would frighten - would frighten Present Perfect - have frightened - have frightened - has frightened - have frightened - have frightened - have frightened Past Perfect - had frightened - had frightened - had frightened - had frightened - had frightened - had frightened Future Perfect - will have frightened - will have frightened - will have frightened - will have frightened - will have frightened - will have frightened Past conditional - would have frightened - would have frightened - would have frightened - would have frightened - would have frightened - would have frightened Imperative - - - frighten - - - - - - - -