Iain -

From what I can gather from searching the Library of Congress catalogs
and other sources, "English as she is taught: being genuine answers to
examination questions in our public schools" was written by Caroline
B. (Bigelow) Le Row and first published in 1887.  Another edition,
published that same year in London, included Twain's commentary of
the book (a review of his taken from Century magazine of April 1887).
There is also a 1900(?) edition of the same title with a biography of
Twain written by Matthew Irving Laws.

"English as she is Spoke" was published by Twain in 1921, but there is
also an interesting listing for the same title "English as she is spoke:
a jest in sober earnest" by Joseda Fonseca (1788-1866) about the English
and Portuguese languages. Interestingly, Twain wrote the introduction to
this edition.

"English as she is Wrote," published in 1884, was a companion to "Spoke".
"English as she is Taught" was also published under the alternate heading
"English as she is Instructed" by Twain, with "A prayer" by Robert Louis
Stevenson.  This edition was published in 1901.

And, lastly, you might be curious to know that there has actually been a
reincarnation of "English as she is Taught" for "mixed choirs and
percussion"!
The score was published in 1978 by Frank Graham Stewart.  THAT might
interest
your class!(I can only find it on microform, by the way.)

Please let me know if any of this helps,

Beth Regish
Smithsonian Libraries