It was very noticeable, when teaching French & Italian in UK schools, that few students and alarmingly many young teachers, had had any practical training in the correct use of English grammar. Nowadays, with the increasing use of mobile technology, it is all too easy to disguise errors in the cause of “efficiency” and to promote the mantra of speedy communication being more important than spelling & grammar. It is an interesting debate. I do not know whether the writer of this sign was a native speaker or not but I am beginning to wonder if (when ?) non-native speakers will soon overtake native speakers in their knowledge and correct usage of English. Certainly the former are adding to and enriching the language. The latter, unfortunately, seem to be travelling in the opposite direction.