The document provides examples of using "for" and "since" to indicate a period of time in different contexts. It lists sample sentences using each preposition to ask how long something has been happening, such as how long someone has been in love, waiting, fighting, in prison, or playing an instrument. The sentences give time periods ranging from minutes to years to demonstrate when to use "for" versus "since" based on whether an action is ongoing or from a starting point in the past.

1. for
a period
(from start to end)
>===<
since
a point
(up to now)
x===>|

2. -HOW LONG HAVE YOU BEEN IN
LOVE?
-We have been in love ………………….last Monday.
…………………. a week.
………………….. five years.
…………………... 2000.
……………………we first met.
FOR
SINCE
FOR
SINCE
SINCE

3. –How long have you been waiting?
-I have been waiting ………………….. an hour.
………………….. eight o’clock.
………………….. half an hour.
………………….. morning.
………………….. ten minutes.
FOR
SINCE
FOR
FOR
SINCE

4. -They have been fighting ………………… last night.
………………… seven hours.
………………… twenty minutes.
………………… Tuesday.
……………… he came there.
–How long have they been fighting?
FOR
SINCE
FOR
SINCE
SINCE

5. –How long have you been in prison?
-I have been here ……………….. Christmas.
………………. January.
……………….. two years.
……………….. I was eighteen years old.
……………….. three months.
FOR
SINCE
SINCE
SINCE
FOR

6. -How long have you been
playing the violin?
-I have been playing the violin
……………….. I was a child.
………………... two and a half hours.
……………….. forty years.
……………….. 1960.
……………….. I bought a violin.
FOR SINCE
FOR SINCE
SINCE

7. -How long have you been
playing the violin?
-I have been playing the violin
……………….. I was a child.
………………... two and a half hours.
……………….. forty years.
……………….. 1960.
……………….. I bought a violin.
FOR SINCE
FOR SINCE
SINCE