Grammatical groanings ... and other grievances

If you didn't enjoy Eats, Shoots and Leaves, then read no further. This blog post will annoy the crap out of you and you will end up thinking I'm some high and mighty wannabe writer. Yes I may be, but we all have our faults.

Along with greengrocers' commas and the misuse of fantastic and few/less etc, something else has been bugging me recently. Have you seen, in a menu for example, the item mash potato? It's either "mash" or "mashED potato". Also skim milk, grrr it's skimmED milk. The milk was SKIMMED, same as the potato was MASHED. Past participle.

Is it just a lazy form of writing? Does it only apply to foodstuffs? Is it just me?