written mode vs spoken

[Chazef]

in an essay prompt like that what kind of things should I be talking about and what examples could I use? thanks

[lzxnl]

So...permanence of the written mode, its impact on literature and history and science etc, the corresponding reviewability of written language, precision and, logically, authority and formality.

For spoken, you could look at its use in social interactions, how slang invariably tends to be spoken for instance, the personal nature of spoken language, spoken language's prosodic features creating sincerity and respect (e.g. relationship breakups; you don't tell by text do you?) etc.

There's a fair bit to choose from; that's what I mentioned in my essay.

As for examples, for written language, think about important written texts there are and how they characterise written language.
For speech, think of famous speeches that exhibited sincerity and respect.