How many sentences should an introduction paragraph have?

There's no magic number of sentences for an introduction paragraph. The ideal length depends entirely on the complexity of the topic and the overall length of the piece of writing. A good introduction generally includes:

* A hook: To grab the reader's attention.

* Background information: To provide context.

* A thesis statement: To clearly state the main point or argument.

Sometimes, this can be accomplished in three sentences. Other times, it might require five or even more. Focus on clarity and effectiveness, not sentence count.