... 25/2/2016 Modal verbs worksheet MODAL VERBS USED TO PERFORM SPECIFIC FUNCTIONS MODAL TIME = TIME = FUNCTION VERB PRESENT& PAST FUTURE COMPULSION ... BUT 'Can't be' or 'can't have been' are used to say that something is not possible: you are CERTAIN http://www.vivquarry.com/wkshts /modal. html 3/6 25/2/2016 Modal verbs worksheet E.g. "Where's John?" "I don't know. He can't still be at home because I've just come from there." or ... When you want to talk about ABILITY ON ONE SPECIFIC OCCASION you must use BE ABLE TO or MANAGED TO http://www.vivquarry.com/wkshts /modal. html 4/6 25/2/2016 Modal verbs worksheet E.g. I wasn't able to fix the engine because I didn't have the parts I needed...