4.6 Apostrophes, Hyphens, and Dashes

4.6 Apostrophes, Hyphens, and Dashes

Apostrophes mark possession or omitted letters rather than ordinary plurals. Learn compound-modifier hyphenation and the different jobs of dashes and hyphens.

3. Apostrophes: Possessives vs. Contractions

Apostrophes serve two distinct functions in English: establishing grammatical possession and signaling missing letters in contractions. The Praxis Core tests candidates' ability to place apostrophes correctly on singular versus plural nouns and to distinguish possessive pronouns from contractions.

Formulating Possessive Nouns

A. Singular Nouns

For ordinary singular nouns, add an apostrophe followed by s. With singular names ending in s, many academic styles also add ’s, while some styles use an apostrophe alone; apply the required style consistently:

• the teacher's lesson plan (one teacher)
• the principal's office (one principal)
• James's classroom or Charles's dissertation (standard academic practice adds -s after the apostrophe for singular proper nouns ending in s).

B. Regular Plural Nouns Ending in -s

To form the possessive of a plural noun that already ends in -s, add only an apostrophe after the s:

• the teachers' lounge (lounge shared by multiple teachers)
• the students' essays (essays written by multiple students)
• the principals' annual conference (conference for multiple principals)

C. Irregular Plural Nouns Not Ending in -s

For plural nouns that do not end in -s, form the possessive by adding an apostrophe followed by s (identical to singular nouns):

• the children's library section (NOT childrens')
• the women's faculty association (NOT womens')
• the people's educational rights

D. Joint vs. Individual Possession

• Joint (Shared) Possession: When two or more nouns possess something together, add -s only to the final noun:
  Maria and David's collaborative research study (one study co-authored by both researchers).
• Individual (Separate) Possession: When two or more nouns possess distinct entities individually, add -s to each noun:
  Maria's and David's respective research studies (two separate studies, one conducted by Maria and one by David).

Possessive Pronouns vs. Contractions (The Ultimate Exam Trap)

Possessive personal pronouns never contain an apostrophe. Contractions always contain an apostrophe to indicate where letters have been omitted. Confusing these homophones is among the most frequent error types in Error Identification items.

Pluralization vs. Possession: The Decades and Acronyms Rule

Do not use an apostrophe simply to make a number, decade, or acronym plural:

• Correct: During the 1990s, educational technology expanded rapidly. (NOT 1990's)
• Correct: The school purchased fifty new PCs for the computer lab. (NOT PC's)

4. Hyphens: Compound Modifiers and Numbers

A hyphen (-) is a mechanical joiner used to unite two or more words into a single compound unit.

Compound Modifiers Preceding a Noun

When two or more words act together as a single adjective before a noun, connect them with a hyphen to eliminate ambiguity:

• an evidence-based instructional strategy (strategy based on evidence)
• a high-stakes standardized examination (examination with high stakes)
• a well-known educational researcher (researcher who is well known)
• a seventh-grade science classroom (classroom for the seventh grade)

Predicate Position: No Hyphen

When the identical descriptive phrase appears after the noun in the predicate (following a linking verb), the words revert to their independent roles, and the hyphen is often omitted; some established compounds retain it, so consult usage rather than imposing an absolute rule:

• The instructional strategy was evidence based. (No hyphen)
• The educational researcher is well known throughout the state. (No hyphen)
• The standardized examination was high stakes. (No hyphen)

The -ly Adverb Exception

When the first word of a compound modifier is an adverb ending in -ly, never use a hyphen. Because an -ly adverb can only modify an adjective or verb, there is zero risk of misinterpretation:

• Correct: a highly qualified secondary mathematics teacher (NOT highly-qualified)
• Correct: a poorly designed assessment rubric (NOT poorly-designed)
• Correct: a recently adopted state curriculum (NOT recently-adopted)

Compound Numbers, Fractions, & Prefixes

• Compound Numbers (21 to 99): Always hyphenate spelled-out numbers from twenty-one to ninety-nine (thirty-five students, seventy-two questionnaires).
• Fractions Functioning as Modifiers: Hyphenate fractions when used as adjectives (a two-thirds majority). Fractions functioning as nouns with intervening prepositions do not require hyphens (two thirds of the faculty voted yes).
• Specific Prefixes: Use hyphens with the prefixes self-, all-, and ex- (self-efficacy, self-directed, all-inclusive, ex-chairperson), and whenever a prefix precedes a capitalized proper noun (pre-Columbian, anti-Federalist, post-World War II).

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5. Dashes: The Em Dash, En Dash, and Hyphen

Standard typography recognizes three horizontal lines of varying lengths, each fulfilling distinct grammatical functions:

Hyphen (-)        Shortest mark; unites compound words (evidence-based, twenty-one)
En Dash (–)       Medium length; indicates ranges of numbers, dates, or pages (pp. 45–60, 2020–2024)
Em Dash (—)       Longest mark; creates an emphatic parenthetical pause or dramatic rhetorical break

The Em Dash (—) in Academic Prose

The em dash creates a pronounced pause—stronger than a comma, but less formal than parentheses. It has two primary uses:

1. Emphasizing an Internal Parenthetical Element: When an internal explanatory phrase contains commas of its own, enclosing it in dashes prevents confusion:
   The three core academic subjects—reading comprehension, written composition, and mathematics—form the bedrock of the teacher licensure battery.
2. Signaling an Abrupt Rhetorical Shift or Summary Concluding Thought:
   The faculty spent three years collecting longitudinal achievement data—only to discover that the state testing standards had been rewritten.