Really quite shocking grammar fails

Really, it's astonishing what errors you can find on printed material. In many cases it shows a real lack of any care at all. Take this photo:

It's a poster for the Xmas party nights on at Newcastle City Hall. This is a local government poster, then, which goes some way towards explaining it; it was almost certainly made by someone with inadequate training, low salary and even less interest in doing it well.

Let's look at what's wrong with it.