What sells slowly, but wears well? Promotion to subject
We have said, several times, that the semantic role which is most likely to be relevant for the success of an activity is placed in syntactic subject relation; this is Mary in Mary sells sports cars, Mary cut the veal with the new knife, Mary poured the custard (onto the pie) with the new jug. If an adverb like quickly, easily, properly or well is added to these sentences it will be taken to describe the way in which the subject performed the activity--Mary certainly sells sports cars quickly, Mary cut the veal easily with the new knife, Mary didn't pour the custard properly (onto the pie) with the new jug (but spilt some on the cloth).
It is possible, in some particular instance of an activity, for the success or lack of success to be due not to the subject (which is usually the responsible role) but to some role in non-subject relation. If this is so, then that role may be promoted into subject slot (and the original subject is omitted from the sentence). For example, Sports cars sell quickly (this implies that it is inherent in the nature of the vehicle that people want to buy them), The veal cuts easily (it isn't tough or sinewy), The new knife cuts veal easily (it is nice and sharp), The custard doesn't pour properly (it has too many lumps in it), The new jug doesn't pour properly (it may have a crooked spout), The new jug doesn't pour custard properly (but it might be all right for water or milk, which have a thinner consistency).
Some linguists have labelled constructions like Sports cars sell