You know it's time to go to bed when...

...my spelling goes horribly wrong.

Recently I've noticed that my spelling degrades significantly once I reach a certain level of tired.  Three examples:

1. Utterly failing to write "cupboard," with attempts like "cuppard" and "cubbord" (1/31/11)
2. "quarner" instead of "corner." (2/14/11)
3. "quartyard" instead of "courtyard" (3/5/11)
4. "whew" instead of "few" (3/11/11) 
5. Switching into French... "mairc" instead of "merci" (6/7/11)

Apparently I have a thing for switching CO's with QUA's.  Franglais-influenced pronunciation, that is.