Possible Duplicate:
Are there any simple rules for article usage (“a” vs “the” vs none)
‘… the weather’ vs. ‘… weather’
“Bad weather doesn't exist” vs. “The bad weather doesn't exist”
I've been learning English for over 10 years now and still don't understand the rules for using articles in phrases like:
Why does one have an article and the other one doesn't. In both phrases we are dealing with abstract, uncountable nouns.
Look closer at the dictionary. Here's a quote from NOAD:
- the feeling of sorrow and compassion caused by the suffering and misfortunes of others: her voice was full of pity.
- [in singular] a cause for regret or disappointment: what a pity we can't be friends.
In your second sentence – what a pity! – the word pity is being used in the sense of Meaning #2; hence, an article is used.
I don't know if this would answer your question under all circumstances, but, in this instance, the root cause of the confusion is one word having multiple meanings, and different grammatical rules for how the word is used in each of those senses.
The use articles in exclamative utterances is no different from the use of articles elsewhere. A occurs before pity, because pity, as J.R.’s reference shows, is used here as a countable noun. Weather is almost always uncountable, and so cannot be preceded by the indefinite article.
