Present participle; Past participle - substituting - substituted Present - substitute - substitute - substitutes - substitute - substitute - substitute Past - substituted - substituted - substituted - substituted - substituted - substituted Future - will substitute - will substitute - will substitute - will substitute - will substitute - will substitute Present conditional - would substitute - would substitute - would substitute - would substitute - would substitute - would substitute Present Perfect - have substituted - have substituted - has substituted - have substituted - have substituted - have substituted Past Perfect - had substituted - had substituted - had substituted - had substituted - had substituted - had substituted Future Perfect - will have substituted - will have substituted - will have substituted - will have substituted - will have substituted - will have substituted Past conditional - would have substituted - would have substituted - would have substituted - would have substituted - would have substituted - would have substituted Imperative - - - substitute - - - - - - - -