Student or Learner
It was clear to me from/since the very beginning.
Which one should I use?
In this sentence, North American speakers would more commonly say 'from the very beginning', but either would be acceptable and might be heard.
We can begin to distinguish between from and since once we bring in a specific end date or time:
Since 1997, our office has been located in Orlando. We typically wouldn't say: 'From 1997, our office has been located in Orlando', but we could.
From 1997 to 2005 our office was located in Orlando, and then we moved to Miami. We wouldn't use since in this example.
These two words, when used as the starting point of a time reference, mean the same thing, but they are not interchangeable. Since needs the present time as the other end, while From can be used with some end date other than now.
It's a tricky distinction, and probably there are examples that might contradict my statements.