Present participle; Past participle - thundering - thundered Present - thunder - thunder - thunders - thunder - thunder - thunder Past - thundered - thundered - thundered - thundered - thundered - thundered Future - will thunder - will thunder - will thunder - will thunder - will thunder - will thunder Present conditional - would thunder - would thunder - would thunder - would thunder - would thunder - would thunder Present Perfect - have thundered - have thundered - has thundered - have thundered - have thundered - have thundered Past Perfect - had thundered - had thundered - had thundered - had thundered - had thundered - had thundered Future Perfect - will have thundered - will have thundered - will have thundered - will have thundered - will have thundered - will have thundered Past conditional - would have thundered - would have thundered - would have thundered - would have thundered - would have thundered - would have thundered Imperative - - - thunder - - - - - - - -