PRESENT PERFECT - FOR / SINCE

WE USE FOR and SINCE AT THE END OF THE SENTENCE

• FOR + A PERIOD OF TIME: ( FOR TWO YEARS/ A LONG TIME/ AGES/ THE LAST WEEK) EXAMPLE: I HAVE STUDIED FOR TWO HOURS
• SINCE + PERIOD OF TIME (MONDAY/ JUNE/ I WAS A CHILD/ LAST WEEK). EXAMPLE: I HAVE STUDIED SINCE 5:00 )