Present participle; Past participle - quadrupling - quadrupled Present - quadruple - quadruple - quadruples - quadruple - quadruple - quadruple Past - quadrupled - quadrupled - quadrupled - quadrupled - quadrupled - quadrupled Future - will quadruple - will quadruple - will quadruple - will quadruple - will quadruple - will quadruple Present conditional - would quadruple - would quadruple - would quadruple - would quadruple - would quadruple - would quadruple Present Perfect - have quadrupled - have quadrupled - has quadrupled - have quadrupled - have quadrupled - have quadrupled Past Perfect - had quadrupled - had quadrupled - had quadrupled - had quadrupled - had quadrupled - had quadrupled Future Perfect - will have quadrupled - will have quadrupled - will have quadrupled - will have quadrupled - will have quadrupled - will have quadrupled Past conditional - would have quadrupled - would have quadrupled - would have quadrupled - would have quadrupled - would have quadrupled - would have quadrupled Imperative - - - quadruple - - - - - - - -