We often use for and since when we are ta...
We often use for and since when we are talking about time.
For
It is used with period of time. For means from the beginning of the period until the end. For can be used with all tenses.
She has been in Vigo for 3 months.
Since
It is used to express the precise moment in time. Since means from a pointin the past until now. Since is normally used with perfect tenses.
She has been in Vigo since July.
