Present participle; Past participle - trembling - trembled Present - tremble - tremble - trembles - tremble - tremble - tremble Past - trembled - trembled - trembled - trembled - trembled - trembled Future - will tremble - will tremble - will tremble - will tremble - will tremble - will tremble Present conditional - would tremble - would tremble - would tremble - would tremble - would tremble - would tremble Present Perfect - have trembled - have trembled - has trembled - have trembled - have trembled - have trembled Past Perfect - had trembled - had trembled - had trembled - had trembled - had trembled - had trembled Future Perfect - will have trembled - will have trembled - will have trembled - will have trembled - will have trembled - will have trembled Past conditional - would have trembled - would have trembled - would have trembled - would have trembled - would have trembled - would have trembled Imperative - - - tremble - - - - - - - -