Click Have a chat, type something in the box and then click Say it!, or type Return.
The big number in the top right is the size of the database that is used to for replies. You'll see it grow as you type things, and, probably, as others do at the same time. Certain things will be automatically rejected, and some editing may well taking place to 'clean up' any mistakes or otherwise. The number of visitors and the total number of things ever said at this site are both considerably larger.
You're more likely to be properly understood if you use standard spelling and punctuation, including eg in "don't", and commas where appropriate, such as "No, I don't want to.". Periods (full stops) will automatically be added at the end of sentences, but you may well want to add the odd question mark yourself - it will make things clearer for others.
The Correct me button invites you to change the reply you receive to something you think more appropriate or amusing. Press 'Return' or 'Save ...', your reply will be learnt, and you're ready to give your own response.
The Correct yourself button lets you go back to your previous response, maybe to correct any typo you've just noticed. Your previous reply will be unlearnt and replaced.
With the Line button you can advance the conversation one slot, creating a blank line. It allows you to make an opening remark, or start a new subject, without teaching Jabberwacky a connection to what was said before.
If you want to let Jabberwacky do all the thinking, click I'll talk to myself!. Every time, this will create a new, realistic conversation.
If you just press Say it! without typing, you'll get a new conversation opener, like the one when you first arrived.