Certain compounds change the form of the first word in pluralizing,
as: _court-martial_, _brother-in-law_, _sister-in-law_. Plural,
_courts-martial_, _brothers-in-law_, etc. "John has three
brother-in-laws," then, is incorrect.
But _tea-spoonful_, _table-spoonful_, _cupful_, _pocketful_, etc., are
not considered such compounds; therefore, "two tea-spoonsful of
medicine" and "two-cupsful of flour," should be, "two tea-spoonfuls of
medicine," and "two cupfuls of flour."
When name and title are given, with a numeral adjective prefixed, the
_name_ is pluralized. "Are the two Misses Wilson at home?" should be,
"Are the two Miss Wilsons at home?" But when the numeral is omitted
the _title_ must be pluralized. "Were the Dr. Browns there?" should
be, "Were the Drs. Brown there?" The rule has been given that the
_name_ only of married ladies is pluralized, but there appears to be
no reason except that of euphony: the _Mrs. Clarks_ certainly sounds
more agreeably than the _Mistresses Clark_. In giving the plural of
such titles as: _Hon._, _Rev._, _Squire_ and _Capt._, euphony is also
often considered; but in such cases it would doubtless be better to
add the numeral, as: the _three Hon. Jacksons_.