The first 20 paragraphs are broad reflections on the nature of language itself, how it is learned, the uses to which it is put etc... Wittgenstein begins with a quotation from Augustine's Confessions about how he learned language by imitating what adults said. I always feel, even reading this passage, that somehow Augustine is being naughty, seeking advantage, being a little rascal by imitating adults to get what he wants, but maybe that's just me projecting my own guilt. Another thing I can't help mentioning is the influence of Chomsky, that language acquisition involves much more than mere imitation, there's complicated structures under the hood -- this seems much less naughty.
One might be tempted to ask: "why the obsession with linguistics, isn't that a science now?"
So, I should say some things about the relationship between our theories regarding language and the problems of philosophy. Philosophy has these 'problems': what's the relationship between our experience and the world? Do other minds exist? How do we know what is right and wrong? What is the best society? What is beauty? What is knowledge? What should be the scientific method? What is the meaning of life? etc... One assessment of why these remain PHILOSOPHICAL problems is that language is somehow going out of bounds with these questions. If language were being used normally the problems would resolve themselves logically or become the subject of some kind of science. These problems point outside of language, and because of this, well, there will always be philosophy professors and mystics somewhere.
To study language is to study why these problems persist, to dilate upon the border between our everyday world and the other, to diagnose the place where the mind goes off the rails. Sometimes philosophers have a kind of 'negative capability', like Nietzsche, but most are irritatingly explicative. One approach is to realize that these problems fail to use language properly and so abandon philosophy as trickery. But over the course of my life I've realized I can't do that. These problems have a kind of undertow to them: once I was made aware of them I couldn't escape them. Mystically, they pull from a place beyond language; non-mystically, language is pushed to the edge and piles up there. No, really, I'm not high.
Just a teaser, Wittgenstein describes language as being composed of games, where words and meanings have rules local to the context. Language itself does not have the single picture presented in the Tractatus. Does this mean that meaning itself is relative to the game? Well, it seems to; the meanings are apparent once one is initiated into the game. But is there a meta-game? Well...