For + a period of time: To measure a period of time up to the present, we use the present perfect tense and not the present tense.
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The present tense with 'For' refers to a period of time that extends into the future.
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Since gives the starting point of actions, events or states. It refers to when things began.
Since + a point in time (in the past), until now.
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With since we use the present perfect tense or the past perfect tense.
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Since can also be used in the structure It has been + period of time + since.
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