In which situation is it not appropriate to use a colon

Read this excerpt from "ain't i a woman? " by sojoumer truth in which three sentences does she make an emotional appeal to the audience by talking about her personal hardships? well, children, where there is so much racket there must be something out of kilter. {i think that 'twixt the negroes of the south and the women at the north, all talking about rights, the white men will be in a fix pretty soon.} but what's all this here talking about? {that man over there says that women need to be into carriages, and lifted over ditches, and to have the best place everywhere. nobody ever me into carriages, or over mud puddles, or gives me any best place} and ain't i a woman? look at me! look at my arm! {i have ploughed and planted, and gathered into bars, and no man could head me! } and ain't i a woman? i could work as much and eat as much as a man - when i could get it - and bear the lash as well! and ain't i a woman? {i have borne thirteen children, and seen most all sold off to slavery, and when i cried out with my mother's grief, none but jesus heard me! } and ain't i a woman? {then they talk about this thing in the head, what's this they call it? [member of audience whispers, "intellect") that's it, honey.} what's that got to do with women's rights or negroes' rights? if my cup won't hold but a pint, and yours holds a quart, wouldn't you be mean not to let me have my little half measure full?

It's to know your purpose before you read something because a purpose can:

4. at the conclusion of frankenstein, robert walton has an encounter with the monster, who arrives after victor frankenstein has died. perhaps surprisingly, the monster mourns his creator and expresses remorse over the fate that victor suffered. the monster pledges to destroy himself and then departs, disappearing as he goes further north. how does the monster’s behavior and attitude in this part of the novel affect the way readers view him? is he sympathetic? is he more hateful because it is only after victor has died that he relents? how does the change in the monster fit with the theme of duality in the novel?