He then looked at other examples of this in newspaper reports and popular media. David Crystal also looked at other examples of non-standard grammar, including double negatives in Beatles songs.
David then told the audience that 'blends' such as 'within how long did it take...' , a combination of 'within what time period' and 'how long did it take' also occur in lectures and he then proceeded to use examples from his own recorded lectures that showed everyone ends up doing this in speech.
Examples of blends rarely appear in public writing, usually, because it is the job of the editor or copy-editor to rephrase any blends that are found. However, some blends do slip through the net. On the Web, in particular, there are examples to be found in social media, Wikipedia, blogs, etc. Taking examples from the top UK blogs, David Crystal showed examples of blends.
The next point David Crystal made was that grammar helps people remember things, and he showed us with examples of strings of numbers of one then two syllables. He also showed examples from ELT, including writing from a 15-year-old.
Over the next week, there will be opportunities to watch (live and recorded) a number of other presentations from the conference as well as interviews of those taking part.
The recording of David Crystal's plenary and the follow up questions can be found below and on the IATEFL Liverpool Online site, http://www.iatefl.org/liverpool-2013/liverpool-2013.