select-grammar-items

name	select-grammar-items
description	Select grammar patterns from data/grammar.json tailored to the learner's current week focus and recent performance, with examples and a practice prompt.

select-grammar-items

When to Use

Invoke this skill when building a daily grammar task or when the learner runs /jp-grammar. It identifies which grammar patterns to teach or reinforce based on where the learner is in the 24-week plan.

Inputs

Parameter	Type	Required	Description
level	string	yes	Learner's current JLPT level: "N5", "N4", "N3"
current_week_focus	string	yes	Week focus area from study plan: "vocab+listening", "grammar+shadowing", "speaking+review"
recent_performance	object	yes	From storage/progress.json: includes recurring_mistakes[], active_grammar_ids[], mastered_grammar_ids[]
count	integer	no	Number of patterns to return. Default: 2.

Outputs

An array of grammar items, each augmented with:

Field	Type	Description
id	string	Grammar item ID
pattern	string	Grammar pattern
level	string	JLPT level
explanation_zh	string	Full Chinese explanation
examples	object[]	Example sentences
topic	string	Topic category
practice_prompt	string	Production task for the learner
selection_reason	string	Why this item was chosen
session_mode	string	"introduce" (new) or "reinforce" (seen before)

Logic

Selection Priority

1. Recurring mistake patterns (highest priority): If recurring_mistakes contains a grammar-related error, find the matching grammar item and return it first with session_mode: "reinforce".
2. Active grammar items: Items in active_grammar_ids that have not been mastered — these need reinforcement.
3. New items for grammar+shadowing weeks: During weeks 9–16, introduce 1–2 new patterns per session.
4. Review mode for speaking+review weeks: During weeks 17–24, rotate through all previously introduced patterns.
5. Low frequency in vocab+listening weeks: Only 1 grammar item per session during weeks 1–8.

Session Mode

• "introduce": Item is new. Show full explanation, all examples, then the practice prompt.
• "reinforce": Item was seen before. Skip lengthy explanation; jump directly to 2 examples and the practice prompt. Show the explanation only if the learner asks.

Level Filtering

Only return items at or below the learner's current level. A level-N5 learner should not receive N4 patterns unless they have explicitly advanced.

Example

Input:

{
  "level": "N5",
  "current_week_focus": "grammar+shadowing",
  "recent_performance": {
    "recurring_mistakes": [{ "pattern": "Omitting の in 〜するのが好き" }],
    "active_grammar_ids": ["grammar_001", "grammar_002"],
    "mastered_grammar_ids": []
  },
  "count": 2
}

Output:

[
  {
    "id": "grammar_003",
    "pattern": "〜が好きです / 〜が嫌いです",
    "session_mode": "reinforce",
    "selection_reason": "matches recurring mistake about omitting の",
    "practice_prompt": "說說你的喜好：你喜歡什麼食物？用「〜が好きです」造3句話。"
  },
  {
    "id": "grammar_004",
    "pattern": "〜に行きます / 〜へ行きます",
    "session_mode": "introduce",
    "selection_reason": "next pattern in N5 travel focus sequence"
  }
]