Since Mother's Day is just around the corner (after all, “if Winter comes, can Spring be far behind?”), the Grammarnator has decided to pay tribute to his mother-in-law by noting that her own personal pet language peeve popped up last week when the Food Snob referred to “the amount of free lunches we would receive” had the Snob gone into politics. Just as the Grammarnator abhors confusion between less and fewer, his normally genial mother-in-law gets upset when someone uses amount instead of number. Not surprisingly, the mistake has the same cause in both cases – a failure to distinguish between something that can be counted or enumerated and something that can't.
In other words, it is possible to have one lunch or two – or six or 16. You can count them. This means that you have a number of lunches, not an amount, and if you skip lunch every other Wednesday, you have fewer lunches some weeks than others. In those weeks, the amount of food you consume decreases; you have less food.
Your wallet contains a number of bills, adding up to a certain amount of money. If you spend some of it, you have fewer bills and less money. The amount of damage done on Halloween depends upon the number of vandals out and about. Fewer vandals means less damage.
If you don't want to go through an involved thought process to figure out which word you should be using, just look for an s or es at the end a word. If it's there (lunches, bills, vandals), you want amount and fewer. If it's not (food, cash, damage), you want number and less.
