Hi folks,
I'm actually on the Livemocha team, and I received a Google Alert this morning for this post. Thanks so much for using
Livemocha to learn English - I hope you enjoy it.
I'm not our content developer or a linguist, but let me take a crack at this because it's a good question and I had to look up the answer :)
Check out David Appleyard's article here:
EnglishToolbox.net | David Appleyard's Guide to Article Usage in English
The absence of an article (a, an, the) is acceptable for words that are abstract ideas (ie. nature), or not countable (water, land). There are exceptions to the rule, like with all other rules in English. And it isn't WRONG to use an article in front of these abstract and uncountable words - so for the ease of learning, I would insert "a, an, the" in front of all words. In other words, treat these strange words like the word bridge.
We should add this feedback to the "tips" on Livemocha. :)
Thanks again for your interest.