Legal Question in Real Estate Law in California

There are generally no 'legal' reasons to break a lease. There may be defenses to being sued if you breach the lease. That doesn't mean you won't be sued. Oral contracts are difficult to prove or enforce. That's why good business sense dictates everything be put in writing.

Mr. Nelson is simply wrong, but the grounds are very limited and require a finding that the premises are not legally inhabitable. He is right, however, that verbal promises are very difficult to prove and enforce, especially if there is a written contract covering the relationship between the parties.

In addition to the discussion in the two prior answers, I'd say to look at your written lease and see if it contains any language such as "this Lease constitutes the entire agreement of the parties" or "this Agreement can be modified only by a writing signed by the parties." Any such language would make it much more unlikely that you could prevail against the landlord if taken to Small Claims for breach of the lease.