I hate to stray so far from the main thread, but anyone who finds E-Prime interesting might enjoy reading about Evidentiality[1]. Some languages allow encoding the nature of evidence in verb forms, with the most cited example (Pomo) having forms to distinguish direct evidence (visual and nonvisual), circumstantial evidence, and hearsay. Somewhat esoteric but pretty cool. Make the observations and give the facts to the listener and let them reach a conclusion - contrast with American English where it is incredibly common to qualify the confidence we have in our own judgement ("It must.." "I suppose.." "I think.." "It probably", and of course all forms of "to be") rather than qualifying the confidence of your knowledge in an objective way.