Check with a lawyer or legal agency about language for your location. 

It’s your responsibility as the landlord to clearly communicate with your tenant.If you want to waste your money and stress a ton, hit him with an eviction notice and get lawyers involved.

An eviction lawyer could help you with some types of general questions and help with a solid lease.

Not a lawyer Is there a clause that you can use for "Reasonable Use" so if they move most of their belongings out you can take possession.

@Kevin Shuler  I'm not a lawyer and this cannot be construed for legal advice, but based on what I know about zoning, if there is not a variance allowing the property to function as a duplex, then you could run into trouble renting it out because if you rent out the units individually and have troubles with either tenant, you will not be able to legally evict them.  

And, I'm a real estate lawyer who reads those regulations and follows each piece of land on the market.We have a group that you can join where information is shared about this process:https://www.meetup.com/We-are-developing-a-tiny-home-village-btwn-Santa-Cruz-SJ/

Cockroach lawyers get paid 200-500 to delay eviction for 6-9 months, rents are at 2k/mo, it's a no brainer to hire them if you really want to screw someone.

lawyer and all fees?

This way she gets more than the $1500 and the lawyer fee goes away saving you $1000.

@Dana Holland, I'm not a lawyer (much to my mother's dismay lol), but I agree with Mindy that doesn't seem like grounds for eviction.Since they are continuously dishonest make sure to document everything.