Just finished an english class talking about speculating, - must / can't etc. Situation: Complete the sentence - I had an argument with my best friend last night.............. Two best replies: 1. The police mustn't find the body. 2. He can't fuck my wife then. I reckon that I am having an effect on them in ways beyond english language, I blame you bastards on here for keeping my sense of humour squaddie orientated.