Sentence Structure and Formation (ACT English)

Complete Sentences

What Makes a Complete Sentence?

A complete sentence must have:

1. Subject (who or what)
2. Predicate (verb and what it does)
3. Complete thought (makes sense on its own)

✓ Complete: "The dog barked loudly."
❌ Incomplete: "The dog barking loudly." (no complete verb)
❌ Incomplete: "Because the dog barked." (not a complete thought)

Sentence Fragments

A fragment is missing a subject, verb, or complete thought

Type 1: Missing Subject

❌ "Ran to the store quickly."
✓ "She ran to the store quickly."

Type 2: Missing Verb or Incomplete Verb

❌ "The students studying for the exam."
✓ "The students are studying for the exam."
✓ "The students studied for the exam."

Note: "-ing" words alone are NOT complete verbs!

Type 3: Dependent Clause Fragment

❌ "Because I was tired."
✓ "Because I was tired, I went to bed early."
✓ "I went to bed early because I was tired."

Common subordinators that create dependent clauses:

• although, because, since, while, when, if, unless, until, after, before

Run-On Sentences

A run-on improperly joins two independent clauses

Type 1: Fused Sentence (Comma Splice)

❌ "I love reading, I visit the library often."
✓ "I love reading**. I** visit the library often." (period)
✓ "I love reading**; I** visit the library often." (semicolon)
✓ "I love reading**, so I** visit the library often." (comma + conjunction)

Type 2: No Punctuation

❌ "The test was hard I studied for hours."
✓ "The test was hard. I studied for hours."
✓ "The test was hard; I studied for hours."
✓ "The test was hard, so I studied for hours."

Ways to Join Sentences

Method 1: Period

Use when: Sentences are complete and independent

✓ "The movie ended. Everyone applauded."

Method 2: Semicolon

Use when: Sentences are closely related

✓ "I love summer; it's my favorite season."

Can also use semicolon before conjunctive adverbs: ✓ "She studied hard; therefore, she passed."
✓ "The weather was bad; however, we went anyway."

Common conjunctive adverbs: however, therefore, moreover, furthermore, nevertheless, consequently

Method 3: Comma + Coordinating Conjunction

FANBOYS: For, And, Nor, But, Or, Yet, So

✓ "I wanted to go, but I was too tired."
✓ "She studied hard, and she passed the exam."

MUST have both comma AND conjunction!

❌ "I wanted to go but I was too tired." (missing comma)
❌ "I wanted to go, I was too tired." (missing conjunction)

Method 4: Subordination

Make one clause dependent:

✓ "Because I was tired, I went to bed."
✓ "I went to bed because I was tired."

Note: Comma rules

• Comma AFTER dependent clause if it comes first
• NO comma if dependent clause comes second (usually)

Sentence Types

Simple Sentence

One independent clause

✓ "The cat slept."
✓ "The large orange cat slept peacefully on the warm couch."

(Still simple even with lots of modifiers — only ONE subject-verb pair doing ONE action)

Compound Sentence

Two or more independent clauses joined

✓ "The cat slept, and the dog barked."
✓ "I wanted pizza; she wanted tacos."

Complex Sentence

One independent clause + one or more dependent clauses

✓ "When I arrived, the party had started." (dependent + independent)
✓ "The book that I borrowed was excellent." (independent with embedded dependent)

Compound-Complex Sentence

Two or more independent clauses + one or more dependent clauses

✓ "When I arrived, the party had started, and everyone was dancing."

Parallel Structure

Items in a list or comparison must have the same grammatical form

Lists

❌ "I like swimming, to run, and biking."
✓ "I like swimming, running, and biking." (all -ing)
✓ "I like to swim, to run, and to bike." (all infinitives)

Comparisons

❌ "The new policy is better than what we had before."
✓ "The new policy is better than the old policy."

Correlative Conjunctions

Pairs: either...or, neither...nor, not only...but also, both...and

Rule: Same structure after each part

❌ "She is not only intelligent but also has creativity."
✓ "She is not only intelligent but also creative." (both adjectives)
✓ "She not only is intelligent but also has creativity." (both verb phrases)

Modifiers

Misplaced Modifiers

Problem: Modifier is too far from what it modifies

❌ "I saw a dog running down the street with a wagging tail."
(Sounds like the street has a wagging tail!)

✓ "I saw a dog with a wagging tail running down the street."

Dangling Modifiers

Problem: What the modifier describes isn't in the sentence

❌ "After studying all night, the exam was easy."
(The exam didn't study!)

✓ "After studying all night, I found the exam easy."
✓ "After I studied all night, the exam was easy."

Common opening modifiers that can dangle:

• After/before + -ing: "After finishing..."
• While + -ing: "While walking..."
• To + verb: "To succeed..."

Rule: Subject of main clause must be what the modifier describes

Wordiness and Redundancy

Redundant Pairs

❌ "first and foremost" → ✓ "first"
❌ "each and every" → ✓ "each" or "every"
❌ "past history" → ✓ "history"
❌ "end result" → ✓ "result"
❌ "completely finish" → ✓ "finish"
❌ "advance planning" → ✓ "planning"

Wordy Phrases

| Wordy | Concise | |-------|---------| | due to the fact that | because | | in spite of the fact that | although | | at this point in time | now | | in the event that | if | | has the ability to | can | | is able to | can | | in order to | to |

Passive Voice

Active (preferred): Subject does the action
Passive: Action is done to subject

❌ "The ball was thrown by John." (passive, wordy)
✓ "John threw the ball." (active, concise)

Passive is okay when:

• Actor is unknown: "The window was broken."
• Actor is unimportant: "The test was administered yesterday."

ACT Question Strategies

Fragment vs Complete

Strategy:

1. Find the verb — is it complete?
2. Find the subject
3. Check if it's a dependent clause standing alone

Red flags for fragments:

• Words ending in -ing with no helping verb
• "Because," "Although," "Since" at start with no main clause
• Missing subject or verb

Run-On Detection

Strategy:

1. Find where one complete thought ends
2. Check if two complete thoughts are properly joined
3. Look for comma splices (just comma between two clauses)

Fix options:

• Period
• Semicolon
• Comma + FANBOYS
• Make one clause dependent

Parallel Structure

Strategy:

1. Identify items in the list/comparison
2. Check they're all the same form (all -ing, all infinitives, all nouns, etc.)
3. Pay attention to "and" — what's before should match what's after

Modifier Questions

Strategy:

1. Find the modifier (usually at start of sentence)
2. Find what it's supposed to modify
3. Make sure they're next to each other
4. Check that the subject of the sentence can logically do what the modifier describes

Common ACT Mistakes

❌ Thinking -ing is a complete verb
"The students working" is NOT complete

❌ Using comma to join two sentences
"I went home, I was tired" is wrong — need semicolon or conjunction

❌ Not matching parallel items
"swimming, to run, biking" — pick one form!

❌ Putting modifier next to wrong word
"Running quickly, the finish line appeared" — finish line can't run!

❌ Keeping redundant phrases
"past history" and "end result" are redundant

❌ Choosing wordy over concise
ACT prefers shorter when meaning is the same

Quick Tips for ACT

✓ Every sentence needs subject + verb + complete thought
✓ "-ing" words need helping verbs (is running, was studying)
✓ Comma alone can't join sentences — need conjunction too
✓ Semicolon = strong period — joins related complete thoughts
✓ Items in list must match form — all nouns, all verbs, etc.
✓ Modifiers describe what comes right after — check logic
✓ Shorter is better — eliminate wordiness
✓ Check FANBOYS — for, and, nor, but, or, yet, so

Decision Tree for Joining Sentences

When you have two complete thoughts:

1. Are they closely related?

   • NO → Use period
   • YES → Continue to #2

2. Do you want to show relationship?

   • NO → Use semicolon
   • YES → Continue to #3

3. What's the relationship?

   • Contrast → , but / , yet / ; however,
   • Addition → , and / ; furthermore,
   • Cause → , so / , for / ; therefore,
   • Alternative → , or
   • Result → , so / ; consequently,

Practice Approach

1. Read the whole sentence — don't just look at underlined part
2. Check for complete thought — subject, verb, makes sense
3. Look for two complete thoughts — are they properly joined?
4. Identify lists or comparisons — check parallel structure
5. Find modifiers — what do they modify? Are they placed correctly?
6. Eliminate wordiness — choose concise option
7. Read with your answer — does it sound right?

Remember: The ACT loves testing fragments, run-ons, and parallel structure. Know how to identify and fix these, and you'll handle many English questions with confidence!