Study guide
3.5 Sound-Change Rules
DLAB Study Guide Exam
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1 Orientation: Current Public DLAB Facts, Score Categories, and Study Model
1.1 What the DLAB Measures 1.2 Known Public Format Facts 1.3 Score Categories and Thresholds 1.4 A Study Model for Aptitude 1.5 Protected-Test Ethics 1.6 Official Channels and a Personal Plan
2 Language-Learning Aptitude: Phonology, Morphology, Syntax, and Working Memory
2.1 What Language-Learning Aptitude Means 2.2 Phonology: Phonemes and Contrast 2.3 Stress, Syllables, and Rhythm 2.4 Morphology: Roots and Affixes 2.5 Syntax and Word Order 2.6 Working Memory and Rule Application
3 Audio Pattern Recognition: Stress, Sound Rules, and Phonetic Discrimination
3.1 One-Pass Listening Mindset 3.2 Stress and Accent Placement 3.3 Syllable Count and Rhythm 3.4 Phonetic Discrimination 3.5 Sound-Change Rules 3.6 Integrated Audio Drills
4 Grammar Rule Extraction: Word Order, Agreement, and Artificial-Language Logic
4.1 Extracting Rules From Examples 4.2 Word Order Patterns 4.3 Agreement Patterns 4.4 Case-Like Endings and Roles 4.5 Plural, Tense, and Negation Markers 4.6 Avoiding English Assumptions
5 Morphology: Roots, Prefixes, Suffixes, Inflection, and Compounding
5.1 Morphemes: Free Forms, Bound Forms, and Meaning Units 5.2 Roots and Stems in Invented Word Families 5.3 Prefixes: Direction, Negation, and Scope 5.4 Suffixes: Inflection, Derivation, and Endings 5.5 Compounding and Meaning Combination 5.6 Tracking Multiple Meaning Changes Under Time Pressure
6 Visual-Symbolic Reasoning: Picture-Word Mapping and Rule Transfer
6.1 Visual-Symbolic Reasoning as Language-Learning Practice 6.2 Mapping Objects, Actions, and Properties 6.3 Multi-Feature Clues and Distractor Control 6.4 Rule Transfer to New Symbols and Scenes 6.5 Avoiding Overfitting and False Patterns 6.6 Timed Visual-Symbolic Practice Method
7 Translation and Sentence Construction From Examples Under Time Pressure
7.1 Translate by Rule, Not by Vocabulary Memory 7.2 Build Sentences From Minimal Examples 7.3 Identify Missing Pieces Before Answering 7.4 Order Elements Without English Assumptions 7.5 Time-Box Hard Construction Items 7.6 Check Consistency and Avoid Overfitting
8 Timed Practice Strategy: Working Memory, Notes, and Error Review
8.1 Pace for a Long Aptitude Test 8.2 Manage Working Memory With Chunking 8.3 Use Notes Without Depending on Universal Rules 8.4 Eliminate Options With Rule Evidence 8.5 Build an Error Log That Teaches 8.6 Build Endurance and Reset Between Items
9 DLIFLC Language Categories, Course Lengths, and Career Path Context
9.1 Why DLIFLC Context Matters 9.2 Public Score Categories and Thresholds 9.3 DLIFLC Course Lengths by Category 9.4 Career Path Context Without Promises 9.5 Multi-Service and Sponsored Attendance 9.6 Turning Category Context Into Study Priorities
10 Service Policy: Scheduling, Waivers, Retests, Clearance, and Job Qualification
10.1 Who Controls the Next Step 10.2 Branch-Specific Score Rules 10.3 Waivers and Exceptions 10.4 Retests and Score Validity 10.5 Clearance and Role Suitability 10.6 Building a Policy-Ready Action Plan
11 High-Yield Practice Drills: Original Examples and Review Routines
11.1 Practice Model and Ethical Boundaries 11.2 Sound and Stress Drills 11.3 Grammar Rule Extraction Drills 11.4 Morphology and Word-Building Drills 11.5 Symbol and Visual Mapping Drills 11.6 Translation, Pacing, and Review Routine
12 Final Review: Test-Day Ethics, Two-Week Plan, and Next Steps
12.1 Two-Week Final Review Map 12.2 Test-Day Logistics and Readiness 12.3 Protected-Test Ethics 12.4 Official-Source Checklist and Policy Questions 12.5 Mindset and Decision Discipline 12.6 After-Score Next Steps and Resources
3.5 Sound-Change Rules
Key Takeaways Explain This Topic AI
A sound-change rule links a change to an environment, so the key question is not just what changed but when it changes.
Use compare-state-test: compare several examples, state the condition in plain words, then test the rule on a new item.
A complete condition names the changing sound, the triggering environment, and at least one example where the sound does not change.
Sound changes often interact with stress, so mark stress first or conditional vowel patterns can look random.
Last updated: June 2026
Listen for the condition
A sound-change rule links a sound change to an environment . The environment might be the next vowel, the previous consonant, the start of a word, the end of a word, or the stressed syllable. For DLAB-style aptitude work the important question is not just what changed; it is when the change happens. Capturing the condition is what separates a usable rule from a vague impression.
Compare, state, test
The core method has three steps:
Compare several examples that share the pattern.
State the rule in plain language, including the trigger.
Test the rule on a new original item before committing.
For instance, in a practice system n might become m before p : san-pa becomes sam-pa , while san-ta stays san-ta . The rule is not " n always becomes m ." The rule is " n changes before p ." That precise condition is what protects you from distractors that contain the right sound in the wrong place.
What a complete condition contains
A condition statement should always include:
The sound that changes .
The environment that triggers the change.
At least one no-change example showing where the rule does not apply.
- Component Practice example Note
- Sound that changes n becomes m The target segment
- Trigger environment before p The condition
- No-change example san-ta stays san-ta Bounds the rule
No-change examples are not filler. They tell you where the condition fails to apply, and a rule that explains both the changed items and the stable ones is far stronger than one that only fits the changes.
Do not overgeneralize from one item
If you hear lom become lon a single time, you do not yet know whether m changes to n , whether all final sounds change, or whether that one word is simply irregular inside the drill. One example suggests; repeated examples confirm. Wait for a second instance before locking in a rule, because committing early to a wrong condition costs you every later item that depends on it.
State rules in small words
Use compact condition words: before, after, at start, at end, when stressed, when followed by . A rule such as " t becomes d between vowels" is far easier to apply under time pressure than a fuzzy memory that the word "sounded softer." Sound changes also interact with stress — an invented system might lengthen a vowel only when it is stressed. Ignore stress and the vowel pattern looks random; mark stress first and the rule becomes predictable. This is why audio prep must combine stress, rhythm, and discrimination rather than train them as isolated tricks.
Apply the condition, not the impression
When answer choices appear, do not let spelling override the heard pattern. The option that looks closest may break the rule. If the examples show n changes only before p , then a choice with m before t is probably wrong even if it feels similar. Review by writing the failed condition precisely: instead of "missed a sound change," write "changed n before t but the rule required change before p." That exact note retrains the ear to ask for the environment automatically, which is the real payoff of sound-change practice — and these remain original drills, never official DLAB items.
Common environments to scan for
When you suspect a sound change, run through a short menu of typical triggers rather than guessing. Most invented-language changes fall into a handful of categories:
Assimilation — a sound shifts to match a neighbor (n becomes m before p, as the labels b/m/p share a lip closure).
Final-position change — a sound at the end of a word weakens, drops, or hardens.
Between-vowels softening — a hard consonant relaxes when surrounded by vowels (k to g, t to d).
Stress-driven change — a vowel lengthens or a consonant strengthens only in the stressed syllable.
Knowing the menu means that when you hear a change, you can immediately test "is the neighbor doing it?" or "is it only at the end?" instead of cataloging every possibility from scratch.
A two-rule interaction example
The DLAB will sometimes stack rules so that two conditions operate at once. Suppose a system both lengthens a stressed vowel and drops a final vowel at the end of a phrase. The word ta-ku in isolation might surface as ta-KUU (stress lengthening), but at the end of a phrase as ta-K (final-vowel drop plus the lengthening no longer audible). A learner who tracks only one rule will hear chaos. A learner who marks stress first, then position can predict both surfaces. When two rules interact, resolve them in a fixed order every time so the output stays predictable rather than mysterious.
Building and self-checking a rule
After you state a candidate rule, run a quick falsification check: find an item where, by your rule, the sound should not change, and confirm it indeed stays. If even one example contradicts the condition, the rule is wrong or incomplete, and it is far cheaper to discover that during the compare step than after committing an answer. A rule that has survived a no-change check is one you can apply to new items with confidence.