+151.+ We have found that the various forms of the participles may be
used as other parts of speech. They partake of the nature of a verb and
either of a noun or an adjective. Notice the following sentences:
Traveling is pleasant.
Eating is necessary.
Can you think of any other way in which you could express the same
thought? Do you not sometimes say,
To travel is pleasant.
To eat is necessary.
We have expressed practically the same thought in these two sentences,
which is expressed in the sentences above, where we used the participle.
_To travel_ and _to eat_ are used as nouns, subjects of the verb _is_
just as _traveling_ and _eating_ are used as nouns, the subjects of the
verb _is_.
Here we have another form of the verb used as a noun. When we use the
verb in this way, we are not speaking of the _traveling_ or _eating_ as
belonging to or being done by any particular person, nor do we indicate
whether one person or more than one is concerned in the action. It might
be anyone doing the traveling or eating, and it might be one person or a
thousand. We are making a general statement of everybody in the world,
so we call this form the _infinitive_.
+152.+ Infinite means _unlimited_, without limit as to persons or
number. Almost every verb in the language may be used in this way, and
since _to_ is generally used before the infinitive, _to_ is often called
the sign of the infinitive. For example:
_To be_, or not _to be_, that is the question.
_To have_ and _to hold_ is the problem.
He likes _to travel_.
You note in all of these infinitives _to_ is used with the simple form
of the verb.
+153.+ _To_ is generally omitted after verbs like _help_, _hear_, _bid_,
_feel_, _let_, _make_, _see_ and _have_, or words of similar meaning.
For example:
Help me (to) find it.
He bade me (to) stay.
Feel it (to) shake.
Make him (to) come.
Hear me (to) sing.
Let us (to) go.
See him (to) run.
Have him (to) copy this.
+154.+ _To_ is also omitted after _need_ and _dare_ when _not_ is used.
They need to work.
They need not work.
They dared to come.
They dared not come.
+155.+ _To_ is sometimes omitted after prepositions:
He will do anything for his class, except (to) fight for it.
He would do nothing but (to) go away.
+156.+ We have a number of different forms of the infinitive, both
active and passive. Note the following table:
+Active+
_Present._ To love.
_Perfect._ To have loved.
_Present Prog._ To be loving.
_Perfect Prog._ To have been loving.
+Passive+
_Present._ To be loved.
_Perfect._ To have been loved.
+157.+ Notice that only the _present_ and _perfect_ infinitives have the
_passive_ form. The progressive infinitives cannot be used in the
passive. Remember also that only _incomplete_ verbs, those which require
an object to receive the action, can have a passive form.
The verb _loved_, which we have used in the above table, has a passive
form because it is an incomplete verb, for there must be that which is
the object of our love.
+158.+ The complete verbs,--verbs which require no object,--cannot have
a passive form for there is no object to become the receiver of the
action. Take for example the verb _dwell_. This is a complete verb which
can have no passive form. You cannot dwell anything, therefore you
cannot say _to be dwelt_ or _to have been dwelt_.
+So complete verbs have only the four active forms+, as follows:
+Active+
_Present._ To dwell.
_Perfect._ To have dwelt.
_Present Prog._ To be dwelling.
_Perfect Prog._ To have been dwelling.
+159.+ Infinitives, like participles, may be used either as nouns or
adjectives. When used as nouns, they are used in the various ways in
which nouns are used. The infinitive may be the _subject_ of a sentence,
thus:
_To hesitate_ now will be fatal.
_To be defeated_ is no crime.
+160.+ The infinitive may be the _object_ or _complement_ of the verb.
For example:
He wanted _to see_ you.
His desire is _to learn_.
+161.+ The infinitive may be used as the object of a _preposition_; as,
He is about _to go_.
They will do anything for the cause except _to live_ for it.
+162.+ The infinitive may be used as an adjective to modify a noun. For
example:
He showed me the way _to go_.
We must have food _to eat_ and clothes _to wear_.
The question _to be decided_ is before us.
Claim your right _to live_.
+163.+ The infinitive may also be used as an adverb to modify the
meaning of a verb, adjective or adverb, thus:
He was forced _to go_.
They are slow _to learn_.
The fruit was not ripe enough _to eat_.
Note that the infinitives in these sentences may all be changed into
adverb phrases. As for example in the first sentence, He was forced _to
go_, the infinitive _to go_, which modifies the verb _forced_, may be
changed to the adverb phrase, _into going_, thus, _He was forced into
going_. In the second sentence, _They are slow to learn_, the infinitive
_to learn_ may be changed into the adverb phrase _in learning_, thus,
_They are slow in learning_. In the last sentence, _The fruit is not
ripe enough to eat_, the infinitive _to eat_, which modifies the adverb
_enough_, may be changed into the adverb phrase, _for eating_, as for
example, _The fruit was not ripe enough for eating_.
+164.+ The infinitive is quite a useful form of the verb, and we will
find that we use it very frequently in expressing our ideas. While it is
not the asserting word in the sentence, it retains the nature of a verb
and may have both an object and an adverb modifier. As for example, in
the sentence: