When a tenant signs a lease, the landlord then has a contractual obligation to allow the person to live in the property. Even though the landlord owns the property, the tenant cannot simply be thrown out without cause. However, there are legal reasons that tenants can be evicted.
First and foremost, if the tenant clearly violates the lease in some way, he or she could be evicted. For instance, if the lease says that the tenant can't have a pet and the tenant then brings a pet into the building or apartment, the landlord may have grounds for eviction if the tenant will not get rid of the pet.
Of course, one of the top reasons that tenants are evicted is simply that they don't pay the rent. A landlord is not going to be able to kick a tenant out immediately -- if the tenant is just a day late on payment, for instance -- but he or she could seek an eviction if non-payment is habitual and some payments are entirely missed, not just late.
Tenants can also be evicted for over-the-top damage. Some damage to the property is expected as normal wear and tear. Additionally, accidents do happen -- someone who slips on the stairs may break a banister, for instance. However, if the tenant is trashing the place, causing significant damage, and ruining the property, the landlord can have him or her evicted.
There is a step-by-step eviction process that must be followed; a landlord can't just show up one day and tell the tenant to leave. It's crucial for both parties to know how this process works and what legal rights they have in New York.
Source: Landlordology, "Top 5 Legal Reasons to Evict a Tenant," Lucas Hall, accessed Sep. 30, 2016