You should look at the comparative adjectives lesson, the superlative adjectives lesson and the (not) as ...as lesson before you study this. Then, when you are ready, test yourself on this lesson with these practice exercises.
Big and small comparisons
We can use other words before a comparative to say how big the difference is.
Love is more important than money.
Love is much / far / a lot more important than money.
(use much, far or a lot for a big difference)
Love is slightly / a bit / a little more important than money.
(use slightly, a bit or a little for a small difference)
We can use other words with superlatives to say how big the difference is.
Whales are by far the biggest animal. (big difference)
Cheetahs are just about the fastest animal. (small difference)
Elephants are one of the biggest animals. (but not the biggest)
Now test yourself on this lesson with these practice exercises.