Present participle; Past participle - sustaining - sustained Present - sustain - sustain - sustains - sustain - sustain - sustain Past - sustained - sustained - sustained - sustained - sustained - sustained Future - will sustain - will sustain - will sustain - will sustain - will sustain - will sustain Present conditional - would sustain - would sustain - would sustain - would sustain - would sustain - would sustain Present Perfect - have sustained - have sustained - has sustained - have sustained - have sustained - have sustained Past Perfect - had sustained - had sustained - had sustained - had sustained - had sustained - had sustained Future Perfect - will have sustained - will have sustained - will have sustained - will have sustained - will have sustained - will have sustained Past conditional - would have sustained - would have sustained - would have sustained - would have sustained - would have sustained - would have sustained Imperative - - - sustain - - - - - - - -