> ## Documentation Index > Fetch the complete documentation index at: https://docs.myspellchecker.com/llms.txt > Use this file to discover all available pages before exploring further. # Grammar Engine > Syntactic rule-based spell checking using POS tags, operating at Layer 2.5 of the validation pipeline to catch errors that N-gram models miss. While N-gram context checking catches many errors through statistical probabilities, some syntactic mistakes like conflicting tense markers, missing case particles, and wrong classifier order require explicit grammatical rules. The Grammar Engine applies YAML-defined POS-sequence rules to flag these patterns. ## Overview ```python theme={null} from myspellchecker.grammar import SyntacticRuleChecker from myspellchecker.providers import SQLiteProvider provider = SQLiteProvider(database_path="path/to/dictionary.db") checker = SyntacticRuleChecker(provider) # Check word sequence corrections = checker.check_sequence(["ကျွန်တော်", "ကျောင်း", "သွားတယ်"]) for idx, error_word, suggestion, confidence in corrections: print(f"Position {idx}: '{error_word}' → '{suggestion}' ({confidence:.0%})") ``` ## Architecture The Grammar Engine coordinates eight specialized checkers: SyntacticRuleChecker Architecture ## Configuration ### GrammarEngineConfig ```python theme={null} from myspellchecker.core.config import GrammarEngineConfig config = GrammarEngineConfig( # Confidence thresholds high_confidence=0.90, medium_confidence=0.85, default_confidence_threshold=0.80, low_confidence_threshold=0.55, # Feature-specific thresholds exact_match_confidence=0.95, context_confidence_threshold=0.65, pos_sequence_confidence=0.80, verb_particle_confidence=0.75, tense_marker_confidence=0.60, sentence_final_confidence=0.70, question_confidence=0.60, ) ``` ### GrammarRuleConfig Load custom grammar rules from YAML: ```python theme={null} from myspellchecker.grammar.config import GrammarRuleConfig config = GrammarRuleConfig(config_path="custom_rules.yml") ``` ## Grammar Rules ### Rule Types | Rule Type | Description | Example | | ------------------ | ------------------------ | ---------------------- | | Particle Typos | Common particle mistakes | ဘူ → ဘူး | | Medial Confusions | Ya-pin vs Ya-yit | ကျောင်း → ကြောင်း | | POS Sequences | Invalid tag combinations | N-N without particle | | Verb-Particle | Verb ending agreement | Missing tense marker | | Sentence Structure | Sentence completeness | Missing final particle | ### Particle Typo Detection ```python theme={null} # Common particle typos loaded from config typo_info = config.get_particle_typo("ဘူ") # Returns: {"correction": "ဘူး", "meaning": "negative ending", "context": "after_verb"} # Check in context corrections = checker.check_sequence(["မ", "သွား", "ဘူ"]) # Detects: "ဘူ" → "ဘူး" (missing visarga in negative ending) ``` ### Medial Confusion Detection Detects common medial character confusions: ```python theme={null} # Ya-pin (ျ) vs Ya-yit (ြ) confusion # ကျောင်း (school) vs ကြောင်း (because) words = ["သွား", "ကျောင်း"] # After verb "go" corrections = checker.check_sequence(words) # Suggests: "ကြောင်း" (because) after verb ``` **Common Confusions:** | Confusion | Characters | Example | | ---------------- | ---------- | ------------------------- | | Ya-pin / Ya-yit | ျ / ြ | ကျောင်း / ကြောင်း | | Wa-swe / Ha-htoe | ွ / ှ | နွေး (warm) / နှေး (slow) | ### POS Sequence Validation Validates POS tag sequences: ```python theme={null} # Invalid: Two nouns without particle words = ["ကျောင်း", "သား"] # school + son corrections = checker.check_sequence(words) # May suggest: "ကျောင်းသား" (student) as compound # Valid: Noun + Subject marker + Verb words = ["သူ", "က", "သွားတယ်"] # he + SUBJ + went corrections = checker.check_sequence(words) # Returns: [] (no errors) ``` **Tag Sequence Rules:** | Sequence | Validity | Reason | | ----------------- | -------- | ------------------------- | | N + V | Warning | Usually needs particle | | V + V | Info | Except auxiliaries (SVC) | | P\_SENT + P\_SENT | Error | Double sentence particles | | N + P\_SUBJ | Valid | Subject marking | ### Verb-Particle Agreement ```python theme={null} # Tense markers must follow verbs words = ["သူ", "ခဲ့"] # he + PAST corrections = checker.check_sequence(words) # Flags: "ခဲ့" (past tense) should follow a verb # Correct usage words = ["သွား", "ခဲ့", "တယ်"] # went + PAST + declarative corrections = checker.check_sequence(words) # Returns: [] (no errors) ``` ### Sentence Structure Validation ```python theme={null} # Missing sentence-final particle words = ["သူ", "သွား"] # he went corrections = checker.check_sequence(words) # Suggests: "သွားတယ်" (adding declarative) # Question without question particle words = ["ဘယ်", "သွား", "မလဲ"] corrections = checker.check_sequence(words) # Validates question word with question ending ``` ## Specialized Checkers ### AspectChecker Validates aspect markers (completion, continuation): ```python theme={null} from myspellchecker.grammar.checkers import AspectChecker aspect_checker = AspectChecker() errors = aspect_checker.validate_sequence(["သွား", "ပြိ"]) # Detects: "ပြိ" → "ပြီ" (completion marker typo) ``` **Aspect Markers:** * `ပြီ` - Completion * `နေ` - Continuation * `ခဲ့` - Past * `မယ်` - Future ### ClassifierChecker Validates Myanmar numeral classifiers: ```python theme={null} from myspellchecker.grammar.checkers import ClassifierChecker classifier_checker = ClassifierChecker() errors = classifier_checker.validate_sequence(["တစ်", "ယေက်"]) # Detects: "ယေက်" → "ယောက်" (person classifier) ``` **Common Classifiers:** * `ယောက်` - People * `ကောင်` - Animals * `လုံး` - Round objects * `ခု` - General objects ### CompoundChecker Validates compound words and reduplications: ```python theme={null} from myspellchecker.grammar.checkers import CompoundChecker compound_checker = CompoundChecker() errors = compound_checker.validate_sequence(["ပန်", "ခြံ"]) # Detects: Missing tone mark → "ပန်းခြံ" (garden) ``` ### NegationChecker Validates negation patterns: ```python theme={null} from myspellchecker.grammar.checkers import NegationChecker negation_checker = NegationChecker() errors = negation_checker.validate_sequence(["မ", "သွား", "ဘူ"]) # Detects: "ဘူ" → "ဘူး" (negative ending) ``` **Negation Patterns:** * `မ...ဘူး` - Colloquial negative * `မ...ပါ` - Polite negative * `မ...` - Literary negative ### RegisterChecker Validates register consistency (formal vs colloquial): ```python theme={null} from myspellchecker.grammar.checkers import RegisterChecker register_checker = RegisterChecker() errors = register_checker.validate_sequence(["သွားတယ်", "ပါသည်"]) # Warns: Mixed register (colloquial + formal) ``` **Register Types:** * Colloquial: `တယ်`, `ဘူး`, `မယ်` * Formal: `သည်`, `ပါသည်`, `မည်`, `ပါမည်`, `၏` ## Integration with SpellChecker The Grammar Engine integrates automatically via validation strategies when rule-based validation is enabled: ```python theme={null} from myspellchecker import SpellChecker from myspellchecker.core.config import SpellCheckerConfig from myspellchecker.providers import SQLiteProvider # Enable grammar checking via use_rule_based_validation config = SpellCheckerConfig( use_rule_based_validation=True, # Enables grammar rules in validation use_context_checker=True, # Context checking includes grammar strategies ) provider = SQLiteProvider(database_path="path/to/dictionary.db") checker = SpellChecker(config=config, provider=provider) result = checker.check("ကျွန်တော် ကျောင်း သွားတယ်") # Grammar errors included in result.errors ``` **Note:** Grammar engine configuration (`GrammarEngineConfig`) is managed internally. For advanced customization, use `SyntacticRuleChecker` directly with a custom config path. ## Custom Rules ### YAML Configuration ```yaml theme={null} # custom_rules.yml particle_typos: "ဘူ": correction: "ဘူး" meaning: "negative ending" context: "after_verb" medial_confusions: "ကျောင်း": correction: "ကြောင်း" context: "after_verb" meaning: "because" invalid_sequences: - prev: "P_SENT" curr: "P_SENT" severity: "error" message: "Double sentence particles" ``` ### Loading Custom Rules ```python theme={null} checker = SyntacticRuleChecker( provider=provider, config_path="custom_rules.yml", ) ``` ## See Also * [Grammar Checkers](/features/grammar-checkers) - Individual checker details * [Validation Strategies](/features/validation-strategies) - Strategy integration * [POS Tagging](/features/pos-tagging) - POS tag reference * [Rules System](/reference/rules-system) - YAML rule files