How you phrase assumptions is crucial for making them testable. Here are two tips:

• Phrase assumptions in a way that they need to be true for your idea to succeed. For example, if you're building a shopping app, a good assumption is: "Users will finish checking out in less than 5 minutes." Avoid phrasing it negatively, like “Users won’t abandon their carts,” since it’s easier to test what users will do than what they won’t.
• Be specific. The more detailed your assumption, the quicker you can test it. Instead of saying, “Users will like the app,” a more testable assumption is: “Users will rate their shopping experience 4 stars or higher.” This allows you to create targeted tests and gather actionable feedback.