It was a few seconds before Mr. Dursley realized that the man was
wearing a violet cloak. He didn't seem at all upset at being almost
knocked to the ground.
Source: Harry Potter and the Philosopher's Stone
Does ‘was’ mean ‘took place’ or is the boldfaced part all an idiom?
Best Answer
In this case, It was a few seconds means A few seconds passed. The construction employs the dummy or expletive *it*, and can be generalized to indicate the ‘presence’ of any extent of time or space:
You can say the same thing as there were; the it was construction favours understanding the duration or distance as a whole, while the there were construction focuses on its measure.
Is it an idiom? It’s a matter of where you draw the line. As J.R. says, it’s tricky to parse; native speakers know what it means, so they don’t have to parse it, but you do have to parse it, so it might as well be an idiom.