| name | vocabulary-tiers |
| description | Guidelines for assigning vocabulary to the three-tier system (basic, core, general). Covers tier criteria, word counts, self-containment principles, and semantic grouping. |
Vocabulary Tier System
This dictionary uses a three-tier vocabulary classification system instead of JLPT levels. This approach provides a pedagogically coherent organization based on actual learner needs rather than test-preparation categories.
Overview of the Three Tiers
Basic Tier (600-800 words)
The most fundamental vocabulary that forms the foundation for any person learning Japanese, regardless of purpose.
Characteristics:
- Words needed from the very first days of study
- High-frequency function words (particles, pronouns, basic conjunctions)
- Essential verbs for daily actions (to be, to go, to eat, to see, etc.)
- Core adjectives for basic description (big, small, good, bad, etc.)
- Numbers, time expressions, and basic counters
- Fundamental nouns (person, thing, place, time, etc.)
- Basic question words (what, who, where, when, why, how)
Target learner: Complete beginner through early intermediate. Someone who has studied for approximately 3-6 months should know most basic tier vocabulary.
Core Tier (1600-2000 words)
Vocabulary expected to be known by any adult using Japanese for work, study, or social life.
Characteristics:
- Words needed for general adult communication
- Common verbs for workplace and social contexts
- Adjectives for nuanced description
- Nouns for everyday life, common objects, and general concepts
- Standard counters beyond the most basic ones
- Conjunctions and transition words for coherent speech/writing
- Words for expressing opinions, emotions, and abstract ideas
Target learner: Intermediate learner through advanced. Someone actively using Japanese in professional or social contexts should know most core tier vocabulary.
General Tier (no word limit)
All vocabulary not classified as basic or core.
Characteristics:
- Specialized or technical vocabulary
- Less frequent words
- Literary or archaic expressions
- Domain-specific terminology
- Regional or dialectal words
- Formal/keigo vocabulary beyond common patterns
- Words for specialized topics (science, law, medicine, etc.)
Target learner: Advanced learners, specialists, or those with specific domain interests.
The Self-Containment Principle
CRITICAL: Both basic and core tiers must be as self-contained as possible for semantically and functionally similar terms.
What This Means
If members of a natural semantic or functional group are included in a tier, all members of that group should be in the same tier. This prevents fragmented learning and ensures pedagogical coherence.
Examples of Self-Containment
Numerals 1-10
If {ไธ|ใใก} is in basic, then ALL of these must be in basic:
- {ไธ|ใใก}, {ไบ|ใซ}, {ไธ|ใใ}, {ๅ|ใ/ใใ}, {ไบ|ใ}, {ๅ
ญ|ใใ}, {ไธ|ใใก/ใชใช}, {ๅ
ซ|ใฏใก}, {ไน|ใ/ใใ
ใ}, {ๅ|ใใ
ใ}
You cannot have {ไธ|ใใก} through {ไธ|ใชใช} in basic and {ๅ
ซ|ใฏใก} through {ๅ|ใใ
ใ} in core.
Days of the Week
If {ๆๆๆฅ|ใใคใใใณ} is in a tier, all seven days must be in that same tier:
- {ๆๆๆฅ|ใใคใใใณ}, {็ซๆๆฅ|ใใใใณ}, {ๆฐดๆๆฅ|ใใใใใณ}, {ๆจๆๆฅ|ใใใใใณ}, {้ๆๆฅ|ใใใใใณ}, {ๅๆๆฅ|ใฉใใใณ}, {ๆฅๆๆฅ|ใซใกใใใณ}
Basic Color Terms
The core color terms should stay together:
- {่ตค|ใใ}, {้|ใใ}, {้ป่ฒ|ใใใ}, {็ฝ|ใใ}, {้ป|ใใ}
If these are in basic, extended colors like {็ดซ|ใใใใ}, {็ฐ่ฒ|ใฏใใใ}, {่ถ่ฒ|ใกใใใ} might reasonably be in core.
Family Terms
Basic family terms should stay together:
- {็ถ|ใกใก}/{ใ็ถใใ|ใใจใใใ}, {ๆฏ|ใฏใฏ}/{ใๆฏใใ|ใใใใใ}, {ๅ
|ใใซ}/{ใๅ
ใใ|ใใซใใใ}, {ๅง|ใใญ}/{ใๅงใใ|ใใญใใใ}, {ๅผ|ใใจใใจ}, {ๅฆน|ใใใใจ}
Question Words
Basic question words form a natural set:
- {ไฝ|ใชใซ/ใชใ}, {่ชฐ|ใ ใ}, {ใฉใ}, {ใใค}, {ใชใ}/{ใฉใใใฆ}, {ใฉใ}, {ใฉใ}, {ใฉใฎ}, {ใฉใกใ}
The Exclusion Corollary
If a semantic group cannot fit entirely within a tier's word limit, move the entire group to a lower-priority tier.
Example: The ๅไบๆฏ (Chinese Zodiac)
If you are drafting the core vocabulary and approaching the 2000-word limit:
- You have included {ๅญ|ใญ} (rat), {ไธ|ใใ} (ox), {ๅฏ
|ใจใ} (tiger) in core
- But adding all 12 zodiac animals would exceed the limit
- Solution: Remove all three and place all ๅไบๆฏ in general tier
This maintains the integrity of the semantic grouping. A learner in the core tier either knows all 12 zodiac animals or noneโthere's no awkward partial knowledge.
Example: Specialized Counter Sets
Counters for small animals ({ๅน|ใฒใ}), flat objects ({ๆ|ใพใ}), and long thin objects ({ๆฌ|ใปใ}) might be core.
But if you're near the limit and have only included 3 of 6 floor-counting counters ({้|ใใ}):
- Either include all floor-related counters in core
- Or move them all to general
Semantic Groups Reference
When assigning tiers, consider these natural groupings:
Groups That Should Stay Together
Time expressions:
- Days of week (7 items)
- Months of year (12 items)
- Hours ({ไธๆ|ใใกใ} through {ๅไบๆ|ใใ
ใใซใ})
- Time periods ({ๆ|ใใ}, {ๆผ|ใฒใ}, {ๅคๆน|ใใใใ}, {ๅค|ใใ}, {ๅคไธญ|ใใชใ})
- Relative time ({ไปๆฅ|ใใใ}, {ๆๆฅ|ใใใ}, {ๆจๆฅ|ใใฎใ}, {ไป้ฑ|ใใใใ
ใ}, etc.)
Numbers:
- Cardinal 1-10 (10 items)
- Cardinal 11-100 by tens (9 additional items)
- Ordinal numbers ({ไธ็ช|ใใกใฐใ}, {ไบ็ช|ใซใฐใ}, etc.)
Basic counters:
- Generic ({ใค} series: {ไธ|ใฒใจ}ใค through {ๅ|ใจใ})
- People ({ไบบ|ใซใ}: {ไธไบบ|ใฒใจใ}, {ไบไบบ|ใตใใ}, {ไธไบบ|ใใใซใ}...)
- Small items ({ๅ|ใ})
- Long thin objects ({ๆฌ|ใปใ})
- Flat objects ({ๆ|ใพใ})
Direction/location:
- Basic directions ({ไธ|ใใ}, {ไธ|ใใ}, {ๅณ|ใฟใ}, {ๅทฆ|ใฒใ ใ}, {ๅ|ใพใ}, {ๅพใ|ใใใ}, {ไธญ|ใชใ}, {ๅค|ใใจ})
- Cardinal directions ({ๅ|ใใ}, {ๅ|ใฟใชใฟ}, {ๆฑ|ใฒใใ}, {่ฅฟ|ใซใ})
Body parts:
- Core set ({้ ญ|ใใใพ}, {้ก|ใใ}, {็ฎ|ใ}, {่ณ|ใฟใฟ}, {ๅฃ|ใใก}, {้ผป|ใฏใช}, {ๆ|ใฆ}, {่ถณ|ใใ}, {ไฝ|ใใใ })
Family:
- Nuclear family terms (as listed above)
- Extended family ({็ฅ็ถ|ใใต}, {็ฅๆฏ|ใใผ}, etc.) may be separate group
Basic verbs:
- Existence ({ใใ}, {ใใ})
- Movement ({่กใ|ใใ}, {ๆฅใ|ใใ}, {ๅธฐใ|ใใใ}, {ๆญฉใ|ใใใ}, {่ตฐใ|ใฏใใ})
- Daily actions ({้ฃในใ|ใในใ}, {้ฃฒใ|ใฎใ}, {ๅฏใ|ใญใ}, {่ตทใใ|ใใใ})
- Communication ({่จใ|ใใ}, {่ฉฑใ|ใฏใชใ}, {่ใ|ใใ}, {่ชญใ|ใใ}, {ๆธใ|ใใ})
Pronouns:
- First person ({็ง|ใใใ}, {ๅ|ใผใ}, etc.)
- Second person ({ใใชใ}, {ๅ|ใใฟ}, etc.)
- Third person ({ๅฝผ|ใใ}, {ๅฝผๅฅณ|ใใฎใใ}, etc.)
- Demonstratives (ใ/ใ/ใ/ใฉ series)
Groups That May Span Tiers
Some semantic groups naturally span tiers based on frequency:
Seasons: {ๆฅ|ใฏใ}, {ๅค|ใชใค}, {็ง|ใใ}, {ๅฌ|ใตใ} โ likely basic or core (keep together)
But season-specific vocabulary (e.g., {็ด
่|ใใใใ}, {ๆข
้จ|ใคใ}) โ may be general
Animals: Common animals ({็ฌ|ใใฌ}, {็ซ|ใญใ}, {้ณฅ|ใจใ}) โ basic/core
Less common ({็|ใใพ}, {็ผ|ใใใใฟ}, {้ฏจ|ใใใ}) โ general
Occupations: Very common ({ๅ
็|ใใใใ}, {ๅป่
|ใใใ}, {ๅญฆ็|ใใใใ}) โ basic/core
Specialized ({ๅผ่ญทๅฃซ|ในใใใ}, {ไผ่จๅฃซ|ใใใใใ}) โ core/general
Decision Criteria for Tier Assignment
Assign to BASIC if the word:
- Is needed in the first weeks/months of study
- Appears in virtually all beginner textbooks
- Is required for basic survival communication
- Is a core grammatical function word (particles, basic conjunctions)
- Is a high-frequency verb/adjective/noun used daily
- Belongs to a fundamental semantic set that should be learned as a unit
Assign to CORE if the word:
- Is needed for general adult communication
- Would be known by any educated Japanese speaker
- Appears regularly in newspapers, general media
- Is used in typical workplace or social situations
- Is an expansion of basic vocabulary (more specific verbs, more nuanced adjectives)
- Belongs to a semantic set appropriate for intermediate learners
Assign to GENERAL if the word:
- Is specialized, technical, or domain-specific
- Is low-frequency in everyday communication
- Is primarily written/literary language
- Is a term that even native speakers might not know without specific exposure
- Is an advanced or formal alternative to common words
- Cannot fit with its semantic group in the core tier due to space limits
Implementation Notes
Tier Realignment Complete (January 2026)
The vocabulary tier realignment project has been completed. The tiers are now fixed at:
- Basic: 795 entries (within 600-800 target)
- Core: 1,998 entries (within 1,600-2,000 target)
- General: 4,566+ entries (no limit)
All entries have been assigned a tier, and semantic groups are kept intact (no groups split across tiers).
For New Entries (IMPORTANT)
All new entries must be assigned to the "general" tier.
Do NOT assign new entries to basic or core tiers. The basic and core tiers have been curated to:
- Meet specific word count targets
- Maintain semantic group integrity
- Cover foundational and adult-communication vocabulary
When creating a new entry, always set:
"metadata": {
"vocabulary_tier": "general",
...
}
The only exception is if explicitly instructed by the user to adjust tier assignments.
For Existing Entries
The basic and core tiers are considered stable. If you need to revise an existing entry:
- Do NOT change its vocabulary_tier unless explicitly instructed
- Basic and core entries were carefully curated to maintain semantic group integrity
Schema Note
Vocabulary tier is stored in the metadata.vocabulary_tier field. Valid values are "basic", "core", or "general".
Examples of Tier Assignment
Example 1: Basic Tier Word
Word: {้ฃในใ|ใในใ} (to eat)
Decision: BASIC
- Needed from very first days of study
- Universal high-frequency action verb
- Part of daily actions verb group (eat, drink, sleep)
- Appears in all beginner textbooks
Example 2: Core Tier Word
Word: {ๆๆก|ใฆใใใ} (proposal, suggestion)
Decision: CORE
- Common in workplace/adult contexts
- Not survival vocabulary but expected of any working adult
- Used in meetings, discussions, business
- Not specializedโgeneral adult vocabulary
Example 3: General Tier Word
Word: {ๅคไพ|ใฏใใใ} (judicial precedent)
Decision: GENERAL
- Legal terminology
- Most adults wouldn't encounter this regularly
- Domain-specific (law)
- Not expected in general communication
Example 4: Applying Self-Containment
Scenario: Assigning the demonstrative series
The ใ/ใ/ใ/ใฉ demonstrative system:
- ใใ/ใใ/ใใ/ใฉใ (things)
- ใใฎ/ใใฎ/ใใฎ/ใฉใฎ (modifiers)
- ใใ/ใใ/ใใใ/ใฉใ (places)
- ใใกใ/ใใกใ/ใใกใ/ใฉใกใ (direction/polite reference)
Decision: All 16 words โ BASIC
Even though ใใกใ/ใใกใ/ใใกใ/ใฉใกใ are slightly less frequent, the demonstrative system is a coherent grammatical unit. Splitting it would create pedagogical confusion.
Example 5: Applying the Exclusion Corollary
Scenario: Core tier is at 1950 words. Considering adding prefecture names.
Japan has 47 prefectures. Adding even the most famous 5 would:
- Fragment the semantic group
- Leave learners with arbitrary partial knowledge
Decision: All prefecture names โ GENERAL
A learner should either know all prefectures or learn them as needed. Partial knowledge of "the 5 most famous prefectures" is not pedagogically useful.
Quality Checklist for New Entries
Note: The decision criteria above (basic/core/general) are historical documentation of how the tiers were curated. They should NOT be used to assign new entries to basic or core tiers. All new entries go to general tier.
