I learned that you can make different meaning depending on your intonation.

For example,

A : How did you like the movie?

B : It was pretty good.

If B says it stressing 'good', then it means that I like it or It was really good.

And if B says it stressing 'pretty', then it means that I didn't like the movie that much.

Here is a question.

I thought the meaning of B saying is basically that the movie is very good. I don't know why the latter has that meaning.

Would you explain this?

EriousB : It was pretty good.
Yes, we use adverbs to qualify an adjective, and the tonality can change the meaning.

It was wonderful / excellent. [Y] [Y] [Y] [Y]
It was very good. [Y] [Y] [Y]
It was quite good. [Y] [Y]
It was good. [Y]
It was pretty good. [Y] [N](If you stress "pretty", it means that I selected this word, and did not choose "very" or "quite", so I didn't think it was very good; it was mediocre.)

It was OK. [Y] [N]
It wasn't very good. [N]
It was bad. [N] [N]
It was terrible / horrible. [N] [N] [N]

But, in slang:
It was BAAAAD ("bad" with long sound for "a") [Y] [Y] [Y]
Appreciate your answer.

It is very easy to understand !