diff --git a/tests/test_i18n.py b/tests/test_i18n.py
index b91e352..9897f1e 100644
--- a/tests/test_i18n.py
+++ b/tests/test_i18n.py
@@ -85,3 +85,76 @@ def test_from_config_defaults_to_english(tmp_path):
 
     d = Dialect.from_config(str(config_path))
     assert d.lang == "en", f"Expected 'en', got '{d.lang}' -- state leak from prior load_lang"
+
+
+def test_de_entity_section_loads():
+    """German entity section loads all pattern lists non-empty."""
+    from mempalace.i18n import get_entity_patterns
+
+    p = get_entity_patterns(("de",))
+    assert p["candidate_patterns"], "de: empty candidate_patterns"
+    assert p["multi_word_patterns"], "de: empty multi_word_patterns"
+    assert p["person_verb_patterns"], "de: empty person_verb_patterns"
+    assert p["pronoun_patterns"], "de: empty pronoun_patterns"
+    assert p["dialogue_patterns"], "de: empty dialogue_patterns"
+    assert p["direct_address_patterns"], "de: empty direct_address_patterns"
+    assert p["project_verb_patterns"], "de: empty project_verb_patterns"
+    assert len(p["stopwords"]) > 50, f"de: stopwords too short ({len(p['stopwords'])})"
+
+
+def test_es_entity_section_loads():
+    """Spanish entity section loads all pattern lists non-empty."""
+    from mempalace.i18n import get_entity_patterns
+
+    p = get_entity_patterns(("es",))
+    assert p["candidate_patterns"], "es: empty candidate_patterns"
+    assert p["multi_word_patterns"], "es: empty multi_word_patterns"
+    assert p["person_verb_patterns"], "es: empty person_verb_patterns"
+    assert p["pronoun_patterns"], "es: empty pronoun_patterns"
+    assert p["dialogue_patterns"], "es: empty dialogue_patterns"
+    assert p["direct_address_patterns"], "es: empty direct_address_patterns"
+    assert p["project_verb_patterns"], "es: empty project_verb_patterns"
+    assert len(p["stopwords"]) > 50, f"es: stopwords too short ({len(p['stopwords'])})"
+
+
+def test_fr_entity_section_loads():
+    """French entity section loads all pattern lists non-empty."""
+    from mempalace.i18n import get_entity_patterns
+
+    p = get_entity_patterns(("fr",))
+    assert p["candidate_patterns"], "fr: empty candidate_patterns"
+    assert p["multi_word_patterns"], "fr: empty multi_word_patterns"
+    assert p["person_verb_patterns"], "fr: empty person_verb_patterns"
+    assert p["pronoun_patterns"], "fr: empty pronoun_patterns"
+    assert p["dialogue_patterns"], "fr: empty dialogue_patterns"
+    assert p["direct_address_patterns"], "fr: empty direct_address_patterns"
+    assert p["project_verb_patterns"], "fr: empty project_verb_patterns"
+    assert len(p["stopwords"]) > 50, f"fr: stopwords too short ({len(p['stopwords'])})"
+
+
+def test_direct_address_key_is_singular_string_for_all_locales():
+    """Schema invariant: any locale declaring direct-address uses the singular
+    ``direct_address_pattern`` (str), never the plural ``direct_address_patterns`` (list).
+
+    The loader at ``mempalace/i18n/__init__.py:209-210`` only reads the singular key;
+    the plural form is the output schema of the merged dict, not the input schema.
+    Declaring the plural form in a locale file silently drops every direct-address
+    pattern in that locale after load.
+    """
+    from mempalace.i18n import _load_entity_section, available_languages
+
+    for lang in available_languages():
+        section = _load_entity_section(lang)
+        if not section:
+            continue
+        assert "direct_address_patterns" not in section, (
+            f"{lang}: declares plural 'direct_address_patterns' (list); "
+            f"loader only reads singular 'direct_address_pattern' (str). "
+            f"Collapse the list into one `|`-alternation string and rename the key."
+        )
+        if "direct_address_pattern" in section:
+            val = section["direct_address_pattern"]
+            assert isinstance(
+                val, str
+            ), f"{lang}: 'direct_address_pattern' must be str, got {type(val).__name__}"
+            assert val, f"{lang}: 'direct_address_pattern' is empty"