y derived from the idea of possession--_have_.

2. Auxiliaries derived from the idea of existence--_be_, _is_, _was_.

3. Auxiliary derived from the idea of future destination, dependent upon
circumstances external to the agent--_shall_. There are etymological
reasons for believing that _shall_ is no present tense, but a perfect.

4. Auxiliary derived from the idea of future destination, dependent upon
the volition of the agent--_will_. _Shall_ is simply predictive; _will_ is
predictive and promissive as well.

5. Auxiliary derived from the idea of power, dependent upon circumstances
external to the agent--_may_.

6. Auxiliary derived from the idea of power, dependent upon circumstances
internal to the agent--_can_. _May_ is simply permissive; _can_ is
potential. In respect to the idea of power residing in the agent being the
cause which determines a contingent action, _can_ is in the same relation
to _may_ as _will_ is to _shall_.

"_May_ et _can_, cum eorum praeteritis imperfectis, _might_ et _could_,
potentiam innuunt: cum hoc tamen discrimine: _may_ et _might_ vel de
jure vel saltem de rei possibilitate, dicuntur, at _can_ et _could_ de
viribus agentis."--WALLIS, p. 107.

7. Auxiliary derived from the idea of sufferance--_let_.

8. Auxiliary derived from the idea of necessity--_must_.

"_Must_ necessitatem innuit. Debeo, oportet, necesse est urere, _I must
burn_. Aliquando sed rarius in praeterito dicitur _must_ (quasi ex
_must'd_ seu _must't_ contractum). Sic, si de praeterito dicatur, _he
must_ (seu _must't_) _be burnt_, oportebat uri seu necesse habuit ut
ureretur."--WALLIS, 107.

9. Auxiliary derived from the idea of action--_do_.

C. _Classification of auxiliary verbs in respect to their mode of
construction._--Auxiliary verbs combine with others in three ways.

1. _With participles._--a) With the present, or active, participle--_I am
speaking_: b) With the past, or passive, participle--_I am beaten_, _I have
beaten_.

2. _With infinitives._--a) With the objective infinitive--_I can speak_: b)
With the gerundial infinitive--_I have to speak_.

3. _With both infinitives and participles._--_I shall have done_, _I mean
to have done_.

D. _Auxiliary verbs may be classified according to their
effect._--Thus--_have_ makes the combination in which it appears equivalent
to a tense; _be_ to a passive form; _may_ to a sign of mood, &c.

This sketch of the different li