for / since

Front

________ a long time

Back

for a long time

Front

________ yesterday

Back

since yesterday

Front

________ an hour

Back

for an hour

Front

_______ 1st May

Back

since 1st May

Front

________ two months

Back

for two months

Front

________ a while

Back

for a while

Front

________ he was a child

Back

since he was a child

Front

________ ten o’clock

Back

since ten o'clock

Front

________ then

Back

since then

Front

_______ many years

Back

for many years