1.
By the time he arrives they will have left.
2. She is ill now. By the first
of April she will have been in hospital for three weeks.
3. He has bought this TV
set on credit. He will have paid all the money by the 21st of August.
4. How
long has she stayed with your family? By the end of the month she will have stayed there for 2 weeks.
5.
She has lived here a long time. By 1990 she will have lived there for 2 years.
6. He is still a school
boy, but by this time next year he will have left school.