Compare situations in which standard formal english is most appropriate to instances in which less formal, colloquial english would be fine in 100 words.

We use standard formal English when communicating with an unknown audience.

Less formal, colloquial English would be fine when communicating with people whom you know and who also know you.

Explanation:

Standard formal English is mostly used in academic writings, job applications, persuasive letters to authorities, business presentations within a company, or to some other company.

Less formal and colloquial English is used when we communicate with people whom we already know, and who also know us. For example communicating with a team lead, group discussion, business meetings within a company, talking to your employer with whom you have already worked for some time.

Below this less formal style comes informal style (though acceptable but not correct) which we use with our close friends, team mates, etc.

The lowest level is slang which is hardly acceptable for most of the people.

Douglass wishes he could write a speech about how easy and delightful life is, but his life and all other african americans' in america has been hard, cruel and miserable. so he gives a speech about truth, how difficult it is to find a glimmer of light in the misery and darkness of slavery. if he were to write an easy and delightful speech, there wouldn't be a point, because at that time african americans were prejudiced against extremely strong and beaten down and treated like animals.  if douglass were to write an easy and delightful speech, it would be about how his brothers and sisters had risen out of slavery and treated as equals; but they're not, so he can't.