Merriam-Webster's Dictionary and Thesaurus - Merriam-Webster [12]
caribou → caribou (sometimes caribous)
moose → moose
There are also some nouns that have a unique plural:
foot → feet
mouse → mice
knife → knives
The Possessive Case
The possessive case of a singular noun is formed by adding an apostrophe followed by an -s:
Jackie's passport
This hat is Billy's
For plural nouns ending in -s, only the apostrophe is added:
the neighbors' dog
both boys' behavior
Proper nouns that end in -s often present a special case:
Mr. Douglas's car
Socrates' teachings
THE PREPOSITION
The preposition is used with an object (a noun, pronoun, or the equivalent of a noun) to form a phrase that functions generally as an adjective or an adverb.
The man in the car is his father. (adjective)
The river winds through the valley. (adverb)
There are two types of prepositions: the simple preposition, which consists of a single word (for example, against, from, near, of, on, out, in) and the compound preposition, which consists of more than one element (for example, according to, on account of, because of, in spite of).
The Conjunction vs. the Preposition
The words after, before, but, for, and since can be used as prepositions or conjunctions. Their part of speech is determined by their function in the sentence. Conjunctions are usually used to connect two elements of the same grammatical type, while prepositions are followed by an object to form a phrase.
Conjunction: The playful but thoughtful youngsters did well in school.
(but connects two adjectives)
Preposition: I was left with nothing but hope.
(but followed by an object)
Conjunction: The device conserves fuel, for it is battery-powered.
(for connects two clauses)
Preposition: The device conserves fuel for better mileage.
(for followed by an object)
Place in the Sentence
A preposition comes in front of a noun or a pronoun (under the desk, beside them), after an adjective (antagonistic to, insufficient for, symbolic of), or after a verb as a particle (take over, put on, come across).
The preposition may end a sentence, especially if it is a verb particle.
What does this all add up to?
After Amy left, Sandra took over.
THE PRONOUN
Pronouns are often said to stand in place of the noun or noun phrase in a sentence. Usually, the pronoun stands for something previously specified or generally understood.
Pronouns have the following characteristics: case (nominative, possessive, or objective); number (singular or plural); person (first, second, or third); and gender (masculine, feminine, or neuter). Pronouns can be classed in seven main categories, each having a specific function.
Demonstrative Pronouns
The words this, that, these, and those are considered as pronouns when they function as nouns. (They are classed as demonstrative adjectives when they modify a noun.) The demonstrative pronoun distinguishes a person or thing from another person or thing:
This is the one I want.
I was happy about that.
These are the best designs.
I picked those as the prettiest flowers.
The demonstrative pronoun also serves to distinguish a person or thing nearby from one that is farther away (this is my desk; that is yours).
Indefinite Pronouns
Indefinite pronouns are used to designate a person or thing of which the identity is unknown or is not immediately evident. The indefinite pronouns include the following:
all
another
any
anybody
anyone
anything
both
each
each one
either
everybody
everyone
everything
few
many
much
neither
nobody
none
no one
one
other(s)
several
some
somebody
someone
something
The indefinite pronoun and the verb that follows it should agree in number. The following pronouns are used with a singular verb: another, anything, each one, everything, much, nobody, no one, other, someone, something:
Much is being done.
No one wants to go.
The indefinite pronouns both, few, many, and several are used with plural verbs:
Many are called; few are chosen.
Certain pronouns, such as all, any,