Question
Can you tell me what the origin of “yobbo” is? (Sam, Year 11 student)
 
Kate's response
This is a straightforward one. Yob is backslang for boy (with yobbo either extending yob with the -o ending). Backslang, as it’s known, was a secret language once used extensively by barrow boys, hawkers, and traders like greengrocers and butchers (1800s), so they could talk without their customers understanding. “Give her some old bit of scrap” would come out Evig reh emos delo tib fo parcs. Backslang appears in the Detective’s Handbook (1882) — it has a glossary of terms like dab “bad”; delog “gold”; helbat “table”; yad “day”. And yob and yobbo are among the few survivors.
 

Question: One of my students had an excellent question. He wanted to know why we call a building a ‘building’ when it is finished being built. Given the use of -ing to indicate continuing action and verbal nouns, it seems a bit odd that never came up with a different word for a ‘building’ once it is completed.
 I was wondering if you have any insights.  (Teacher English Language)
 
Kate's response: Great question! The original job description of -ing was to form nouns — at first nouns of action but then during the medieval period the suffix expanded to include a broader range of nouns, and also included things which resulted from the action (like building etc.).

It’s interesting that the earlier form in Old English was -ung and the suffix that formed the past participle of veerbs was -ende — somehow these two endings collided to form the -ing we have in the modern language (so two suffixes merged and hence we find today a rather confusing array of functions for -ing).

Hope this makes sense!
 

Question
In a heated debate with my classmates and teacher, we were discussing whether or not 'Balloon.' is a sentence. Don't ask how we got there, we tend to get quite off track. I decided to solve the debate I'd email you. Is this a sentence (let's say you see a balloon and state 'Balloon').  (VCE student - Billy)

Kate's response
Such a good question. There are some very complex analyses of these kinds of structures (treating them as examples of ellipsis, and reconstructing an underlying verb, for example such as "Look, balloon!"), but I never see much point in these sorts of abstract analyses (seems unhelpful to analyse something like "Exit" in terms of "Here is the exit" or "This is the exit"!). 
 
I'd simply call this a ‘sentence fragment’ or ‘clause fragment’. This would put it in the same bucket as other verbless clauses like "What a disaster!" and also verbless directives such as “Careful”!, “Two coffees”, “All aboard”! etc. (But something like your example “Balloon!” is also a little like an interjection, isn't it — so something like “Hell”! “Crumbs”! “Wow”! “Pssst”! “Shhh”! etc.). 
 
This isn't terribly satisfactory I know, given the label ‘sentence fragment’ includes a whole heap of constructions that happen to be missing crucial bits and pieces like (normally obligatory) verbs and subjects (and the bête noire of many editors and teachers!).