Hello, and welcome. I am a licensed attorney and happy to assist.
For landlord, this is a great question, and I'm glad you asked.
A landlord can evict a tenant who is under a lease (1) at the end of the lease; (2) for nonpayment of rent; (3) for breach of a rule stated in the lease; (4) or if the landlord needs the tenant out for substantial repairs/remodel. A landlord can also evict a month-to-month tenant at any time, and for any reason (that doesn't constitute a civil rights violation) upon 30 days notice.
For each type of eviction, there is are specific notice requirements. If you would like more information about the process that pertains to your particular circumstances, just let me know and I'll be happy to elaborate.
I hope this helps. If you need additional information or clarification, just let me know and I'll be happy to continue providing assistance. If I have addressed your issue and/or pointed you in a positive direction, please let me know that as well, and please remember to leave a positive rating when prompted, as that is the only way attorneys on this site are credited for the information we provide.