Digraph Detectives Worksheet
GRADE 3 PHONICS • CASE #301 Standard: CCSS RF.3.3 Multisyllable Decoding
DIGRAPH DETECTIVES: 3RD GRADE EDITION
Agent Name:
Date:
Score:
3RD GRADE DETECTIVE RULE:
A consonant digraph is two letters that team up to make one sound. Break words into syllables to find them!
1
Mission A • Syllable Sleuth: Multisyllabic Breakdown
Separate each word with dots (•), then write the hidden digraph.
1. dolphin 2 syllables
Syllables:
Digraph:
2. thunderstorm 3 syllables
Syllables:
Digraph:
3. champion 2 syllables
Syllables:
Digraph:
4. whispering 3 syllables
Syllables:
Digraph:
5. accomplish 3 syllables
Syllables:
Digraph:
6. triumph 2 syllables
Syllables:
Digraph:
2
Mission B • The 3 Sounds of "CH" Codecracker
Sort each word by how its "ch" sounds!
sandwich echo chef chimney chemistry parachute
/ch/ like chair Standard English Sound
/k/ like school Greek Word Origin
/sh/ like machine French Word Origin
3
Mission C • The Vocal Cord Test: Voiced vs. Unvoiced "TH"
Place your fingers on your throat. Does it vibrate or stay quiet?
Voiced /ð/ (Throat Vibrates) e.g., father, breathe
1. feather Vibrates? [ ]
2. brother Vibrates? [ ]
3. weather Vibrates? [ ]
Unvoiced /θ/ (Quiet Whisper Air) e.g., thunder, math
1. author Quiet Air? [ ]
2. panther Quiet Air? [ ]
3. athlete Quiet Air? [ ]
Investigation Case File #301 • 3rd Grade Phonics Master Level Page 1 of 2
DIGRAPH DETECTIVES • CASE FILE #301 (PART 2)
Proofreading, Mystery Case Reading & Sentence Writing
Agent Name:
4
Mission D • Proofreading: Catch the Misspelled Digraphs
Find the misspelled word in bold and write the correct spelling.
1. Liam captured a clear fotograph of the dinosaur skeleton.
Correct:
2. The gym teacher blew his silver wistle to start the game.
Correct:
3. The magician wore a spooky mask like a mysterious fantom.
Correct:
4. We rested comfortably in the shade beneth the tall oak tree.
Correct:
5. Maya loves learning about atoms and reactions in kemistry class.
Correct:
5
Mission E • Mystery of Midnight Manor Case Log
Fill in the story with the best digraph clue words.
whispered shadow thunderstorm photograph character echo
During a loud midnight (1), Detective Maya arrived at the manor. Lightning flashed across the front porch, creating a giant dark (2) on the wooden floor.
Inside the library, every step made a hollow (3) bounce off the stone walls. Maya pulled out a black-and-white (4) of the missing safe. "Look behind the bookshelf!" (5) Professor Vance, a clever (6) who knew every secret in town.
6
Mission F • Agent Field Notes: Write Your Own
Write full 3rd-grade sentences meeting each detective rule.
CHALLENGE 1 Write a sentence containing at least one ph word and one sh word:
CHALLENGE 2 Write a sentence with a compound word that contains a digraph (e.g., thunderstorm, sunshine, whiteboard, whirlpool):
Investigation Case File #301 • 3rd Grade Phonics Master Level Page 2 of 2
Digraph Detectives Answer Key
TEACHER KEY • CASE #301 Grade 3 Phonics Standard CCSS RF.3.3
DIGRAPH DETECTIVES: 3RD GRADE KEY
MASTER ANSWER KEY Total Points: 30 Points
TEACHING NOTE:
3rd grade phonics emphasizes multisyllabic decoding, etymological sound variations of "ch", and orthographic conventions.
1
Mission A Solutions • Syllable Sleuth Breakdown
1 pt per word (6 pts)
1. dolphin
Syllables: dol • phin
Digraph: ph (/f/)
2. thunderstorm
Syllables: thun • der • storm
Digraph: th (/θ/)
3. champion
Syllables: cham • pi • on
Digraph: ch (/ch/)
4. whispering
Syllables: whis • per • ing
Digraph: wh (/w/)
5. accomplish
Syllables: ac • com • plish
Digraph: sh (/sh/)
6. triumph
Syllables: tri • umph
Digraph: ph (/f/)
2
Mission B Solutions • The 3 Sounds of "CH"
1 pt per word (6 pts)
/ch/ like chair English Origin
sandwich
chimney
/k/ like school Greek Origin
echo
chemistry
/sh/ like machine French Origin
chef
parachute
3
Mission C Solutions • Voiced vs. Unvoiced "TH"
1 pt each (6 pts)
Voiced /ð/ (Throat Vibrates) Buzzing sound
1. feather ✓ VIBRATES
2. brother ✓ VIBRATES
3. weather ✓ VIBRATES
Unvoiced /θ/ (Quiet Whisper Air) Breath only
1. author ✓ QUIET AIR
2. panther ✓ QUIET AIR
3. athlete ✓ QUIET AIR
Investigation Case File #301 • 3rd Grade Phonics Master Level Page 1 of 2
DIGRAPH DETECTIVES • CASE FILE #301 (PART 2)
3rd Grade Answer Key & Scoring Rubric
TEACHER KEY
4
Mission D Solutions • Proofreading Digraphs
1 pt each (5 pts)
1. Error: fotograph (substituting 'f' for digraph 'ph')
Correct: photograph