By writing and performing short dialogues, adults and teens can practice using count and noncount (uncountable) nouns with definite and indefinite articles. Students could write these dialogues alone or in pairs. Teachers should focus only on the correct use of the target grammar and vocabulary, and not worry about other errors. The important thing is that students use the vocabulary in grammar in a meaningful way, and their errors do not impede communication.
This activity has been used effectively in ESL 2 (high beginning) with middle and high school students.