d,
in the other instances, it is not properly the verb _do_, that is the
substitute, but rather the word that follows it--or perhaps, both. For,
since every action consists in _doing something_ or in _doing somehow_,
this general verb _do_, with _this, that, it, thus_, or _so_, to identify
the action, may assume the import of many a longer phrase. But care must be
taken not to substitute this verb for any term to which it is not
equivalent; as, "The _a_ is certainly to be sounded as the English
_do_."--_Walker's Dict., w. A_. Say, "as the English _sound it_;" for _do_
is here absurd, and grossly solecistical. "The duke had not behaved with
that loyalty with which he ought to have _done_."--_Lowth's Gram._, p. 111;
_Murray's_, i, 212; _Churchill's_, 355; _Fisk's_, 137; _Ingersoll's_, 269.
Say, "with which he ought to have _behaved_;" for, to have _done_ with
loyalty is not what was meant--far from it. Clarendon wrote the text thus:
"The Duke had not behaved with that loyalty, _as_ he ought to have done."
This should have been corrected, not by changing _"as"_ to _"with which"_,
but by saying--"with that loyalty _which_ he ought to have _observed;"_ or,
"_which would have become him"_.

OBS. 19.--It is little to the credit of our grammarians, to find so many of
them thus concurring in the same obvious error, and even making bad English
worse. The very examples which have hitherto been given to prove that _do_
may be a substitute for other verbs, are _none of them in point_, and all
of them have been constantly and shamefully _misinterpreted._ Thus: "They
[_do_ and _did_] sometimes also supply the place of _another verb_, and
make the repetition of it, in the same or a subsequent sentence,
unnecessary: as, 'You attend not to your studies as he _does_;' (i. e. as
he _attends_, &c.) 'I shall come if I can; but if I _do not_, please to
excuse me;' (i. e. if I _come_ not.)"--_L. Murray's Gram._, Vol. i, p. 88;
_R. C. Smith's_, 88; _Ingersoll's_, 135; _Fisk's_, 78; _A. Flint's_, 41;
_Hiley's_, 30. This remark, but not the examples, was taken from _Lowths
Gram._, p. 41. Churchill varies it thus, and retains Lowth's example: "It
[i. e., _do_] is used also, to supply the _place of another verb_, in order
to avoid the repetition of it: as, 'He _loves_ not plays, As thou _dost_,
Antony.' SHAKS."--_New Gram._, p. 96. Greenleaf says, "To prevent the
repetition of _one or more verbs_, in the same, or [a] following sentence,
we frequentl