Tenant not paying rent or vacating what can I do

Hi, My tenant is a senior citizen and living in my apartment for past one year. He lived in my adjacent flat for two years and asked me to move into my flat for a month so I believed him and therefore no lease agreement was made. he started giving excuse after excuse whenever I asked him to pay the rent and now when I asked him to vacate the place, he just keeps saying i have no mone and give me time. It is already been 11 months. I am now sensing thatb he is in no mood to either pay or vacate. I am scared as if I use force, then my case will be weakened. So what should I do ? help.