Present participle; Past participle - impairing - impaired Present - impair - impair - impairs - impair - impair - impair Past - impaired - impaired - impaired - impaired - impaired - impaired Future - will impair - will impair - will impair - will impair - will impair - will impair Present conditional - would impair - would impair - would impair - would impair - would impair - would impair Present Perfect - have impaired - have impaired - has impaired - have impaired - have impaired - have impaired Past Perfect - had impaired - had impaired - had impaired - had impaired - had impaired - had impaired Future Perfect - will have impaired - will have impaired - will have impaired - will have impaired - will have impaired - will have impaired Past conditional - would have impaired - would have impaired - would have impaired - would have impaired - would have impaired - would have impaired Imperative - - - impair - - - - - - - -