Rental agreements may be both oral or written agreements. Written agreements are usually preferred, because they offer more protection under the law. Rental agreements may also be either fixed term agreements, where a tenant leases a property for a specific amount of time, or periodic agreements, which are open ended with no defined expiration date. Periodic agreements are usually on a month to month basis, though they can also be week to week. A landlord may evict a tenant with a periodic rental agreement at any time, as long as he gives the tenant proper notice. Tenants with fixed term leases have more protection against eviction, and can only be evicted for nonpayment of rent or a lease violation. No matter what kind of rental agreement a tenant has, a landlord can not personally throw out a tenant. Evicting tenants with month to month rental agreements or leases with fixed terms can only be accomplished though court action.