Present participle; Past participle - sirening - sirened Present - siren - siren - sirens - siren - siren - siren Past - sirened - sirened - sirened - sirened - sirened - sirened Future - will siren - will siren - will siren - will siren - will siren - will siren Present conditional - would siren - would siren - would siren - would siren - would siren - would siren Present Perfect - have sirened - have sirened - has sirened - have sirened - have sirened - have sirened Past Perfect - had sirened - had sirened - had sirened - had sirened - had sirened - had sirened Future Perfect - will have sirened - will have sirened - will have sirened - will have sirened - will have sirened - will have sirened Past conditional - would have sirened - would have sirened - would have sirened - would have sirened - would have sirened - would have sirened Imperative - - - siren - - - - - - - -