What is different between "very good" and "pretty good"?
You can think of "pretty good" as being more casual and hip than "very good." The latter sounds a little more formal and rigid than "pretty good," although both work fine in this context. Ex: The movie was pretty good! Sometimes, "pretty good," depending on tone, can also be used to indicate some reluctance or a feeling of "more or less." In these cases, we can understand it to mean "it was so-so." Ex: A: How is your summer break going? B: Pretty good, I guess. (Not bad).