S and N bought a store building and took title as joint tenants. N died testate. S now owns the store:

When S and N took title to the store building as joint tenants, they established a form of ownership that includes the right of survivorship. This means that when one joint tenant dies, the surviving tenant automatically inherits the deceased tenant's share.

In the scenario where N died testate, meaning there was a will, the situation changes regarding ownership. Since N's interest in the property as a joint tenant would extinguish upon death, it would not pass to N's heirs as part of his estate. Instead, S would take full ownership of the property as the surviving joint tenant, thereby owning it in severalty. This form of ownership means that S holds the title solely in their name, without any rights of N or N's heirs.

The concept of survivorship ensures that the joint tenant ownership bypasses probate and directly transfers ownership to the surviving joint tenant. This is a key feature of joint tenancy that distinguishes it from other ownership forms, such as tenancy in common, where ownership could pass to heirs. Therefore, S now owns the store building independently, which is defined as ownership in severalty.