Words and bottled water

When I teach a poetry class, I sometimes like to bring in poems in multiple translations. I find that reading across translations helps students to sharpen their awareness of how any word in a poem can make a significant difference to the whole. But it always happens that someone who's less of a nominalist than me will insist that the translations are all saying the same thing, just with different words.

I just thought about this matter when writing the words "bottled water" in a short piece for lifehack.org -- some advice for students about finding a good place to study. Here are two sentences, almost identical, yet they still don't say the same thing. These are sample sentences; neither is from what I've written for lifehack:

When I got home, I drank bottled water and graded essays.

When I got home, I drank a bottle of water and graded essays.

In the first sentence, drinking bottled water is an ongoing activity, something that accompanies work. That may be the case with the second sentence too, but the second sentence is more easily read as a matter of discrete, consecutive activities. The difference in meaning lies in the difference between an undefined amount ("water") and a unit ("a bottle"). I can hear the same difference in similar pairs -- "coffee," "a cup of coffee"; "cigarettes," "a cigarette." (Granted, "cigarettes" involves a number, not an amount.) Such distinctions -- clear to someone who knows the language, elusive and tenuous to someone who's learning it from scratch -- are good reminders that if the words are different, they're not saying the same thing.