This question tests your understanding of verb forms in reported speech and conditional structures. The sentence "I assured him that he ___________ pneumonia" requires a verb that matches the context of assurance about a future possibility.

Step 1: Analyze the main verb
The main verb is "assured," which indicates a promise or guarantee about a future outcome.

Step 2: Identify the appropriate tense
When we assure someone about something that might happen in the future (especially something negative we want to prevent), we typically use "wouldn't" to express future negation in a conditional way. "Wouldn't get" indicates "would not get" - a future possibility being denied.

Step 3: Evaluate the options

• "Shouldn't get" implies advice or recommendation, not assurance
• "Gets" is present tense and doesn't match the future context
• "Wouldn't get" correctly expresses future negation following assurance
• "Get" is the base form and doesn't convey the intended meaning

Final Answer: The correct option is "wouldn't get"
Complete sentence: "I assured him that he wouldn't get pneumonia."

Related Concepts

Reported Speech: When reporting assurances, promises, or predictions about the future, we often use "would" as the future-in-the-past form.

Conditional Structures: "Wouldn't" is used here to express a conditional future outcome - the assurance that under normal circumstances, pneumonia won't occur.

Key Formula

Subject + assured + (someone) + that + subject + would/wouldn't + base verb