Present participle; Past participle - understudying - understudied Present - understudy - understudy - understudies - understudy - understudy - understudy Past - understudied - understudied - understudied - understudied - understudied - understudied Future - will understudy - will understudy - will understudy - will understudy - will understudy - will understudy Present conditional - would understudy - would understudy - would understudy - would understudy - would understudy - would understudy Present Perfect - have understudied - have understudied - has understudied - have understudied - have understudied - have understudied Past Perfect - had understudied - had understudied - had understudied - had understudied - had understudied - had understudied Future Perfect - will have understudied - will have understudied - will have understudied - will have understudied - will have understudied - will have understudied Past conditional - would have understudied - would have understudied - would have understudied - would have understudied - would have understudied - would have understudied Imperative - - - understudy - - - - - - - -