Thanks to a heads-up from a reader yesterday, noticed that loads of links are broken as they are all trying to go to https://www./files/ with no name of the site in it. Seems to be sorted now, but if it goes wrong again try:
- manually add usingenglish.com to the missing bit of the link
- Paste that incomplete link into Google
- Google the name of the thing that you are looking for
Links to other sites all seem to be working.
TEFLtastic 
About half fixed, and working on the others now.
Seems sorted now, but please let me know if you come across any other broken links.