I always just buy clothes when I get there.
Dear Word Detective: I was playing a memory game with the kids called “Pack the Suitcase,” which led me to think about the word “suitcase.” You can have one or more suitcases, and can also shorten it to “case,” as in “I have two cases with me.” Then there’s baggage — we all have a lot of it, don’t we? One bag, or much “baggage.” But what about luggage? “I have quite a bit of luggage.” Works fine. But “I have only one lug with me”? No, I think not. Needless to say, I lost the memory game, but perhaps you can crack this case. — Margherita Wohletz.
So, memory games, eh? Around here we call that “going to the supermarket.” Sure, we make lists. But the cats sneak into the kitchen at night and edit them. Next thing you know, you’re standing in Aisle Nine looking for things like “toona icecream” and “mouseburgers.” Meanwhile, you’ve completely forgotten that you’re out of vital necessities like pizza and doughnuts.
Onward. There are two aspects to your question, so it’s probably best to handle them separately. The more general is the subject of “count” (or “countable”) nouns versus “mass” nouns in English. “Suitcase” is a countable noun; you can say “I have six suitcases” (or, as you say, “two cases”). Most English nouns are countable, and they can take modifiers denoting number (“six cups”) or more general quantifiers, as in “many cats,” “several cars,” “every student,” etc.
“Baggage” and “luggage,” however, are mass nouns, and in English you can’t say “I have six luggages” or “I have only one baggage.” You can’t even say “I have many luggages.” With mass nouns we use more general terms like “little” and “much.” In general, mass nouns tend to refer to a kind of thing in a collective sense rather than individually; although “suitcase” and “luggage” describe the same thing, “luggage” is a more general “mass” term for the class of containers you take on a trip.
The fact that mass nouns refer to a class made up of count nouns does not, however, mean that there is literally a count noun lurking inside every mass noun, ready to be pried out by pruning away prefixes and suffixes. Thus “garbage,” a mass noun, cannot be deconstructed to infer that one trash bag might be called a “gar,” or that the “lug” in “luggage” might be an old word for “suitcase.”
The “lug” in “luggage” is, in fact, not a noun at all but the familiar verb “to lug,” meaning “to drag, pull or carry with great effort,” which first appeared in English in the early 14th century, probably from Scandinavian roots. The magic bit in “luggage” and similar nouns is the suffix “age,” which we borrowed from Old French (which adapted it from Latin), and which generally forms abstract nouns with a collective sense (luggage, plumage, tonnage), based on a condition or position of a person (orphanage, parsonage), or based on an action (damage, breakage, postage). So “luggage” basically means “things to be lugged.” Samuel Johnson, by the way, defined “luggage” in his 1755 dictionary as “any thing of more weight than value.”
“Baggage,” which first appeared in English in the 15th century, is not as clear an application of the “age” suffix as “luggage” is, because it arrived in English more fully-formed. We adapted “baggage” from the Old French “bagage,” meaning “property picked up for transport,” from the Old French verb “baguer,” meaning “to tie up.” The roots of the Old French point to the same source as produced our English “bag,” but although “bag” is suspected to be of Old Norse origin, no one knows for sure. In any case, the “bag” in “baggage” is not simply our modern noun “bag.” The effect of the “age” suffix is the same, though, producing the sense of “things and property to be collected and transported.”