Present participle; Past participle - concentrating - concentrated Present - concentrate - concentrate - concentrates - concentrate - concentrate - concentrate Past - concentrated - concentrated - concentrated - concentrated - concentrated - concentrated Future - will concentrate - will concentrate - will concentrate - will concentrate - will concentrate - will concentrate Present conditional - would concentrate - would concentrate - would concentrate - would concentrate - would concentrate - would concentrate Present Perfect - have concentrated - have concentrated - has concentrated - have concentrated - have concentrated - have concentrated Past Perfect - had concentrated - had concentrated - had concentrated - had concentrated - had concentrated - had concentrated Future Perfect - will have concentrated - will have concentrated - will have concentrated - will have concentrated - will have concentrated - will have concentrated Past conditional - would have concentrated - would have concentrated - would have concentrated - would have concentrated - would have concentrated - would have concentrated Imperative - - - concentrate - - - - - - - -