Explanation

Error Source.

For and Since pose problems for German learners of English because the two words are translated in German with one word, Seit; a word that resembles the English word Since and means since but not in all contexts.

Unlike in German there is a difference between SINCE (a specific time) and FOR (a space of time.)

Example:

Er lebt seit drei Jahren in Deutschland. (Space of time) = FOR

Er lebt seit 2010 in Deutschland. (Specific time) = SINCE

Both prepositions are Seit but the English cannot translate all the two with SINCE.

Three years is a length of time so the English translate:

seit drei Jahren with for three years.

But when Seit is used in the sense of a date, a year, a day then since is used.

So:

seit 2010 means since 2010.

NB: Since and For are strong indicators for the use of the Present perfect continuous. He has been working since 2010

H e has been working for three years.

For - a period of time, a space of time, a length of time.

for three hours

for a week

for five years I have been working for two hours.

for a long time

for a number of days

for a number of hours

for a couple of years etc.

Since- a specific time, the time when the action began.

Since 2010

since Monday

since last year I have been living in Germany since 1990.

since Easter

since 1945

since my childhood

since this morning

since 12 o'clock

So far the difference is clear but there is another little trick to quickly know when to use since or for.

When it is possible to use the German word lang instead of the word seit, then use For.

seit 10 Jahren- 10 Jahren lang - f or 10 years

seit 5 Minuten- 5 Minuten lang - for 5 minutes

seit drei Wochen- drei Wochen lang- for three weeks

seit zwei Tage- zwei Tage lang- for two days

seit drei Stunden- drei Stunde lang- for three hours

BUT

seit 1990 1990 lang is bad German since 1990

seit heute Morgen since today morning

seit 13 Uhr- since one o'clock.