Complete ACT Grammar and Punctuation Rules
The Critical Reader, http://www.thecriticalreader.com
Punctuation
I. APOSTROPHES
Apostrophes make nouns possessive
For singular nouns, always add apostrophe + -s
The boy's ball = The ball belonging to the boy
The dress's buttons = The buttons on the dress
For plural nouns, always add -s + apostrophe (or -es + apostrophe if the singular version
ends in -s)
The boys' ball = The ball belonging to the boys
The dresses' buttons = The buttons on the dresses
Pronouns: no apostrophe = possessive
It's vs. Its
It's = It is
Its = Possessive form of "it'
Its' = Does not exist
Incorrect: London is a city known for it's (it is) many tourist attractions.
Correct: London is a city known for its) many tourist attractions.
Incorrect: London is a popular tourist attraction; in fact, its among the most visited cities in
the world.
Correct: London is a popular tourist attraction; in fact, it's among the most visited cities in
the world.
They're vs. Their vs. There
They're = they are
Their = possessive form of "they"
There = a place
© 2015 Erica Meltzer, The Critical Reader, http://www.thecriticalreader.com
, They're
Correct: London and Paris are two of the most famous cities and Europe, and they're (they
are) known for having many tourist attractions.
Their
Correct: London and Paris are known for their many tourist attractions.
There
Incorrect: In the nineteenth century, Paris was considered the capital of the art world
because so many famous painters lived and worker there.
Who's vs. Whose
Who's = Who is
Correct: Barbara McClintock is a scientist who's (who is) best known for her discovery of
"jumping" genes.
Whose = Possessive of who
Correct: Barbara McClintock is a scientist whose discovery of "jumping" genes helped earn
her the 1983 Nobel Prize in Physiology or Medicine.
Note that "whose," unlike "who," can be used for both people and things/places.
Correct: London is a city whose many museums, palaces, and monuments make it a popular
tourist destination.
II. SEMICOLONS & PERIODS
Semicolon = Period
Semicolons are used:
1. Between two complete sentences
London is an old city; it has many new buildings.
2. Before conjunctive adverbs such as however, moreover, and therefore when they are
used to begin a clause
London is an old city; however, it has many new buildings.
London is an old city; therefore, it has buildings from many different eras.
Note: ACT grammar questions testing however will use a semicolon in the correct
version whereas rhetoric questions will use a period.
© 2015 Erica Meltzer, The Critical Reader, http://www.thecriticalreader.com
The Critical Reader, http://www.thecriticalreader.com
Punctuation
I. APOSTROPHES
Apostrophes make nouns possessive
For singular nouns, always add apostrophe + -s
The boy's ball = The ball belonging to the boy
The dress's buttons = The buttons on the dress
For plural nouns, always add -s + apostrophe (or -es + apostrophe if the singular version
ends in -s)
The boys' ball = The ball belonging to the boys
The dresses' buttons = The buttons on the dresses
Pronouns: no apostrophe = possessive
It's vs. Its
It's = It is
Its = Possessive form of "it'
Its' = Does not exist
Incorrect: London is a city known for it's (it is) many tourist attractions.
Correct: London is a city known for its) many tourist attractions.
Incorrect: London is a popular tourist attraction; in fact, its among the most visited cities in
the world.
Correct: London is a popular tourist attraction; in fact, it's among the most visited cities in
the world.
They're vs. Their vs. There
They're = they are
Their = possessive form of "they"
There = a place
© 2015 Erica Meltzer, The Critical Reader, http://www.thecriticalreader.com
, They're
Correct: London and Paris are two of the most famous cities and Europe, and they're (they
are) known for having many tourist attractions.
Their
Correct: London and Paris are known for their many tourist attractions.
There
Incorrect: In the nineteenth century, Paris was considered the capital of the art world
because so many famous painters lived and worker there.
Who's vs. Whose
Who's = Who is
Correct: Barbara McClintock is a scientist who's (who is) best known for her discovery of
"jumping" genes.
Whose = Possessive of who
Correct: Barbara McClintock is a scientist whose discovery of "jumping" genes helped earn
her the 1983 Nobel Prize in Physiology or Medicine.
Note that "whose," unlike "who," can be used for both people and things/places.
Correct: London is a city whose many museums, palaces, and monuments make it a popular
tourist destination.
II. SEMICOLONS & PERIODS
Semicolon = Period
Semicolons are used:
1. Between two complete sentences
London is an old city; it has many new buildings.
2. Before conjunctive adverbs such as however, moreover, and therefore when they are
used to begin a clause
London is an old city; however, it has many new buildings.
London is an old city; therefore, it has buildings from many different eras.
Note: ACT grammar questions testing however will use a semicolon in the correct
version whereas rhetoric questions will use a period.
© 2015 Erica Meltzer, The Critical Reader, http://www.thecriticalreader.com
