In many ways, the tone of this diary is youthful. Anne does have many surprisingly mature insights into life, war, interpersonal relationships, and much more. However, this is always set against the general youthful tone of her writing. She has concerns that are typical of adolescents such as boys, arguments with her parents, all that. She frequently talks about wanting to be grown up already and she often gets all giddy about the boy she likes. It’s not a criticism that her tone is youthful; it ought to be, given her age.
Anne’s writing also tends to be optimistic. She seems to be like her dad in that way. She is generally optimistic about life within the Secret Annex, and thankful for her family’s protection. But at times Anne can complain or grow angry about conditions or how others treat her, or be righteously angry at fellow Annex members for being selfish. She cleverly points out ironies in her domestic life and the political situation she’s wrapped up in, and can’t resist indulging in humor, usually regarding fellow members of the Secret Annex.