It's not just you that doesn't know. Now, according to owl.purdue.edu, we should use "doesn't" when the subject is singular (except when the subject is "you" or "I"), and "don't" otherwise. But in the example above, I am having a hard time figuring out what exactly the subject is and whether it is singular.

Get personalized homeowners insurance coverage for accidents in your home, giving you peace of mind and financial security to protect your investment. Homeowners insurance coverage and policy specifics can vary based on where you live. Check out our Homeowners Insurance by State page to learn more about state-specific options.

Homeowners insurance can help you ease the financial burden of repairing or rebuilding your home and replacing your belongings after certain commonplace disasters — like a fire, lightning strike, tornado or even a break-in. It also can help cover your costs in a lawsuit over an injury or property damage.

See the best homeowners insurance companies in Wyoming and explore what home insurers offer in the state for coverage, rates and discounts.

Find and connect with the 6 Best Homeowners Insurance Agencies in Cheyenne, WY. Hand picked by an independent editorial team and updated for 2026.

Why do you think that He doesn't know him from his schooldays means that he does know him? It would only have that sense if you added something like In fact, he first met him at university.