er common mistake is the confusion of the nominative and objective
cases in objective clauses where two pronouns or a noun and a pronoun
occur.

All this was done for you and I.

is a very common but entirely inexcusable mistake. One would hardly
think of saying

"All this was done for I."

I saw John and he leaving the shop.

is almost equally common and quite equally bad. Do not allow yourself to
be confused by a double object.

In general great care should be taken to avoid ambiguity in the use of
pronouns. It is very easy to multiply and combine pronouns in such a way
that while grammatical rules may not be broken the reader may be left
hopelessly confused. Such ambiguous sentences should be cleared up,
either by a rearrangement of the words or by substitution of nouns for
some of the pronouns.

_Adverbs_

An adverb is a helper to a verb, "I fear greatly," "that press works
badly." Adverbs modify or help verbs, adjectives, and other adverbs just
as adjectives modify nouns and pronouns. The use of adverbs presents
some difficulties, mainly arising from the adverbial use of many other
parts of speech and from the close relation between adverbs and
adjectives.

It should never be forgotten that while adverbs never modify nouns or
pronouns, adjectives never modify anything but nouns or pronouns.
Remembrance of this simple fact will settle most questions as to the use
of adverbs or adjectives. Careful observation and care in forming
correct habits of expression will do the rest.

Do not multiply negatives. They cancel each other like the factors in an
arithmetical problem. "He never did wrong" is correct in statement and
clear in meaning. "He never did nothing wrong" does not add force, it
reverses the meaning. The negatives have cancelled each other and you
are saying "He did wrong." "He never did nothing wrong to nobody" leaves
us with an odd negative and brings us back to the first statement, very
badly expressed.

_Prepositions_

A preposition is a hook for a noun or pronoun to hang on. It usually
precedes the noun or pronoun which hangs, or depends upon it, as
indicated by its name which is derived from the Latin _pre_-before and
_pono_-I place.

John is behind the press.

I shall work until Sunday.

A preposition shows the relation of a noun or pronoun used as its object
to some other word or words in the sentence or, as it has been otherwise
stated, ma