emphasis You use imaginable after a word like `every' or `all' to emphasize that you are talking about all the possible examples of something. You use imaginable after `no' to emphasize that something does not have the quality mentioned. Parents encourage every activity imaginable. = possible
emphasis You use imaginable after a superlative such as `best' or `worst' to emphasize that something is extreme in some way. their imprisonment under some of the most horrible circumstances imaginable = conceivable