Use "For" and "Since" for Time (Tenses)

For and Since for Time

We often use for and since when talking about time.

.جب ہم وقت کی بات کرتے ہیں تو فور اور سینس کا استعمال کرتے ہیں

for + period
A period is a duration of time, for example: 5 minutes, 2 weeks, 6 years. For means "from the beginning of the period until the end of the period." For can be used with all tenses.

since + point
A point is a particular moment in time, for example: 9 o'clock, 1st January, Monday. Since means "from a point in the past until now." Since is normally used with perfect tenses.

For and Since for Time
For	Since
a Period (from start to end) >===<	a Point (up to now) x===>|
for 20 minutes for three days for 6 months for 4 years for 2 centuries for a long time for ever etc	since 9am since Monday since January since 1997 since 1500 since I left school since the beginning of time etc
all tenses	perfect tenses only

For can be used with all tenses. Here are a few examples:

• They study for two hours every day.
• They are studying for three hours today.
• He has lived in Bangkok for a long time.
• He has been living in Paris for three months.
• I worked at that bank for five years.
• Will the universe continue for ever?

For is NOT used with "all day", "all the time" etc.

• I was there all day. (not *for all day)

Since is normally used with perfect tenses:

• He has been here since 9am.
• He has been working since he arrived.
• I had lived in New York since my childhood.

Since can also be used in the structure "It is [period] since...":

• It is a year since I saw her.
• How long is it since you got married?