P2: Articles and Nouns: Use articles when appropriate based on count or noncount nouns. See Writing for Success Section 5.3 pp. 183-186 or the following: http://grammar.ccc.commnet.edu/grammar/determiners/determiners.htm
Use articles with count nouns.
A cat is trapped on the roof – Correct
Cat is trapped on the roof — Incorrect
The cat is licking its paws. – Correct
Cat is licking its paws. – Incorrect
Don’t use articles with non-count nouns.
Smiling can put people at ease. – Correct
The smiling can put people at ease. – Incorrect
Jonah’s dog appeared to have rabies. – Correct
Jonah’s dog appeared to have the rabies. – Incorrect