The pedant in me: Speaking good English != Writing good English

Let me first qualify my post by saying that I do not speak nor write perfect English.

Of all places I found this at an exhibition at the Central Public Library (Bugis). On top of that, there were "Speak good English, yes I can" (can't remember the exact words) flag banners (sorry, no pic) outside the library adding to the irony. Or maybe the banners were literal (see post title).