When narrating and summarizing, keep your tenses straight.
In the example below, the writer begins by describing what Demi
recalls. The writer’s subsequent switch into the past tense is fine
(the concert happened in the past), but the switch back to the present
tense is not fine.
Shifting Tense: In
the second chapter, Demi recalls attending the concert to see her
best friend perform. At first she found the event slow and tedious,
but eventually she gets interested and stops feeling so sleepy.
Remember, shifting between different tenses is fine
as long as each shift is logical and done on purpose.