Use for or since i've lived in washington 1997. ben has studied english three years. they haven't visited their grandparents months. julie's ill. she's been in bed tuesday. my dad has had his sixteen. it's been ten we moved to oxford.

I've lived in Washington SINCE 1997.
Ben has studied English FOR three years.
They haven't visited their grandparents FOR months.
Julie's ill. She's been in bed SINCE Tuesday.
My dad has had his car SINCE sixteen.
It's been ten years SINCE we moved to Oxford.