Time Has Flown By

Help me ... Does time pass so fast or so fast? 3

This sentence is true .. I don't know how much time has passed so fast ..

Fly so fast

Time has passed

Or don't know when time flies so fast.

Or I don't know when time flies so fast.

It depends on when you want to use it and the nuances of the meaning you want to convey.

Time Has Flown By

It's time to fly so fast.
The second will apply to rds (for example, because your question is in the rds section) in phrases like: rds happened so fast that I can't identify the type.
Flu
First of all, a bad place to ask a question ... it should have been in another category ... otherwise the answer time passes so fast!
Time is single, so the words are right. I don't know if time has passed so fast, yes, your sentence is correct.