N3
ずっと ②
By far, Way, Far...er, Far...more
さっき見た鳥よりずっと大きかったよ!
It was much bigger than the bird we saw earlier.
Explanation
This 「ずっと」 is used in comparisons, modifying an adjective or adverb, and means 'much' or 'far': 「この店のほうが、あの店よりずっと安い」 (This shop is far cheaper than that one). It often goes with 「より」 or 「比べて」 to stress the contrast. It is common in speech and writing.
Mixed up with
「ずっと」 (1) (N4) means 'all the time': 「ずっと待っていた」 (I've been waiting all along). 「ずっと」 (2) (this one) means 'by far': 「ずっと安い」. Look for 「より」 in the sentence to tell which.
「ずっと」 is everyday and neutral. More formal writing prefers 「はるかに」.