The tenant cannot legally break their lease unless there is a specific provision added to the lease. There are times when it makes sense to allow a tenant to break their lease if they cover the cost of finding a new tenant. But this rarely happens and the owner is required to approve.
If tenants break their lease, they must pay rent until the property is leased to a new tenant or until their lease expires. In addition, they may pay advertising costs, real estate commissions and other costs directly related to efforts to lease the property.